ELECTROWETTING DEVICES

ELECTROWETTING DEVICES

INCORPORATION BY REFERENCE OF RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 62/675,085, filed May 22, 2018, the entire contents of which is incorporated herein by reference and made a part of this specification.

BACKGROUND

Field of the Disclosure

Some implementations of this disclosure relate to electrowetting devices, such as liquid lenses.

Description of the Related Art

Many aspects of electro wetting devices have been of interest previously. Use of such devices have been applied generally to optical devices, but many challenges remain.

SUMMARY

Certain example embodiments are summarized below for illustrative purposes. The embodiments are not limited to the specific implementations recited herein. Embodiments may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to the embodiments.

Some aspects of the present disclosure can relate to an optical device (e.g., a liquid lens) that includes a chamber, a first fluid contained in the chamber; a second fluid contained in the chamber, and an interface between the first fluid and the second fluid. The chamber can have a substantially planar surface and a raised surface surrounded at least in part by the substantially planar surface. The raised surface can be disposed on an optical axis of the optical device. The device can have one or more electrodes that are insulated from the first and second fluids. The device can have interdigitated electrodes, in some implementations. One or more electrodes can be in electrical communication with the first fluid. The optical device can be an optical switch in some cases.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments will be discussed in detail with reference to the following figures, wherein like reference numerals refer to similar features throughout. These figures are provided for illustrative purposes and the embodiments are not limited to the specific implementations illustrated in the figures.

Figure 1 is a cross-sectional view of an example implementation of a liquid lens.

Figure 2 shows the liquid lens in a second state where a voltage is applied.

Figure 3 shows a plan view of an example implementation of a liquid lens.

Figure 4 shows a cross-sectional view taken through opposing electrodes.

Figure 5 show an example portion of a liquid lens.

Figure 6A shows an example electrowetting device with a plurality of fluid interface states shown.

Figure 6B shows an example electrowetting device having a compensating optical feature.

Figures 7A - 7E show the example electrowetting device of Figure 6A with the fluid interface at various states.

Figure 7F shows an example implementation of an electrowetting device.

Figures 8A - 8F show example electrode arrangements for use in an electro wetting device.

Figures 9A - 9C show an example optical device that includes an electro wetting device.

Figure 10 shows an example implementation of an optical device with an array of optical couplers.

Figure 11 shows an example implementation of an electro wetting device configured to form a plurality of fluid interfaces.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Liquid Lens Systems

Figure 1 is a cross-sectional view of an example implementation of a liquid lens 10 The liquid lens 10 can have a cavity 12 that contains at least two fluids (e.g., liquids), such as a first fluid 14 and a second fluid 16 The two fluids can be substantially immiscible so that a fluid interface 15 is formed between the first fluid 14 and the second fluid 16 Although some embodiments disclosed herein have a fluid interface between two fluids that directly contact each other, the interface can be formed by a membrane or other intermediate structure or material between two fluids. Thus, various embodiments disclosed herein can be modified to use various different fluids, such as those that could mix if in direct contact. In some embodiments the two fluids 14 and 16 can be sufficiently immiscible such as to form the fluid interface 15. The interface 15, when curved for example, can refract light with optical power as a lens. The first fluid 14 can be electrically conductive, and the second fluid 16 can be electrically insulating. The first fluid 14 can be a polar fluid, such as an aqueous solution, in some implementations. The second fluid 16 can be an oil, in some implementations. The first fluid 14 can have a higher dielectric constant than the second fluid 16. The first fluid 14 and the second fluid 16 can have different indices of refraction, for example so that light can be refracted at it passes through the fluid interface 15. The first fluid 14 and the second fluid 16 can have substantially similar densities, which can impede either of the fluids 14 and 16 from floating relative to the other.

The cavity 12 can include a portion having a shape of a frustum or truncated cone. The cavity 12 can have angled side walls. The cavity 12 can have a narrow portion where the side walls are closer together and a wide portion where the side walls are further apart. The narrow portion can be at the bottom end of the cavity 12 and the wide portion can be at the top end of the cavity 12 in the orientation shown, although the liquid lenses 10 disclosed herein can be positioned at various other orientations. The edge of the fluid interface 15 can contact the angled side walls of the cavity 12. The edge of the fluid interface 15 can contact the portion of the cavity 12 having the frustum or truncated cone shape. Various other cavity shapes can be used. For example, the cavity can have curved side walls (e.g., curved in the cross-sectional view of Figures 1-2). The side walls can conform to the shape of a portion of a sphere, toroid, or other geometric shape. In some implementations, the cavity 12 can have a cylindrical shape. In some implementations, the cavity can have a flat surface and the fluid interface can contact the flat surface (e.g., as a drop of the second fluid 16 sitting on the base of the cavity 12).

A lower window 18, which can include a transparent plate, can be below the cavity 12. An upper window 20, which can include a transparent plate, can be above the cavity 12. The lower window 18 can be located at or near the narrow portion of the cavity 12, and/or the upper window 20 can be located at or near the wide portion of the cavity 12. The lower window 18 and/or the upper window 20 can be configured to transmit light therethrough. The lower window 18 and/or the upper window 20 can transmit sufficient light to form an image, such as on an imaging sensor of a camera. In some cases, the lower window 18 and/or the upper window 20 can absorb and/or reflect a portion of the light that impinges on thereon.

A first one or more electrodes 22 (e.g., insulated electrodes) can be insulated from the fluids 14 and 16 in the cavity 12, such as by an insulation material 24. A second one or more electrodes 26 can be in electrical communication with the first fluid 14. The second one or more electrodes 26 can be in contact with the first fluid 14. In some implementations, the second one or more electrodes 26 can be capacitively coupled to the first fluid 14. Voltages can be applied between the electrodes 22 and 26 to control the shape of the fluid interface 15 between the fluids 14 and 16, such as to vary the focal length of the liquid lens 10. Direct current (DC) voltage signals can be provided to one or both of the electrodes 22 and 26. Alternating current (AC) voltage signals can be provided to one or both of the electrodes 22 and 26. The liquid lens 10 can respond to the root mean square (RMS) voltage signal resulting from the AC voltage(s) applied. In some implementations, AC voltage signals can impede charge from building up in the liquid lens 10, which can occur in some instances with DC voltages. In some implementations, the first fluid 14 and/or the second one or more electrodes 26 can be grounded. In some implementations, the first one or more electrodes 22 can be grounded. In some implementations, voltage can be applied to either the first electrode(s) 22 or the second electrode(s) 26, but not both, to produce voltage differentials. In some implementations, voltage signals can be applied to both the first electrode(s) 22 and the second electrode(s) 26 to produce voltage differentials.

Figure 1 shows the liquid lens 10 in a first state where no voltage is applied between the electrodes 22 and 26, and Figure 2 shows the liquid lens 10 in a second state where a voltage is applied between the electrodes 22 and 26. The chamber 12 can have one or more side walls made of a hydrophobic material. For example the insulating material 24 can be parylene, which can be insulating and hydrophobic, although various other suitable materials can be used. When no voltage is applied, the hydrophobic material on the side walls can repel the first fluid 14 (e.g., an aqueous solution) so that the second fluid 16 (e.g., an oil) can cover a relatively large area of the side walls to produce the fluid interface 15 shape shown in Figure 1. When a voltage is applied between the first electrode 22 and the first fluid 14 (e.g., via the second electrode 26), the first fluid 14 can be attracted to the first electrode 22, which can drive the location of the fluid interface 15 down the side wall so that more of the side walls are is in contact with the first fluid 14. Changing the applied voltage differential can change the contact angle between the edge of the fluid interface 15 and the surface of the cavity 12 (e.g., the angled side wall of the truncated cone portion of the cavity 12) based on the principle of electrowetting. The fluid interface 15 can be driven to various different positions by applying different amounts of voltage between the electrodes 22 and 26, which can produce different focal lengths or different amounts of optical power for the liquid lens 10.

Figure 3 shows a plan view of an example implementation of a liquid lens 10. In some implementations, the first one or more electrodes 22 (e.g., insulated electrodes) can include multiple electrodes 22 positioned at multiple locations on the liquid lens 10. The liquid lens 10 can have four electrodes 22a, 22b, 22c, and 22d, which can be positioned in four quadrants of the liquid lens 10. In other implementations, the first one or more electrodes 22 can include various numbers of electrodes (e.g., 1 electrode, 2 electrodes, 4 electrodes, 6 electrodes, 8 electrodes, 12 electrodes, 16 electrodes, 32 electrodes, or more, or any values therebetween). Although various examples are provided herein with even numbers of insulated electrodes 22, odd numbers of insulated electrodes 22 can also be used. The electrodes 22a-d can be driven independently (e.g., having the same or different voltages applied thereto), which can be used to position the fluid interface 15 at different locations on the different portions (e.g., quadrants) of the liquid lens 10. Figure 4 shows a cross-sectional view taken through opposing electrodes 22a and 22c. If more voltage is applied to the electrode 22c than to the electrode 22a, as shown in Figure 4, the fluid interface 15 can be pulled further down the sidewall at the quadrant of the electrode 22c than at the quadrant of the electrode 22a. The electrode 26 can be a common electrode. The electrodes 22a-d can be driving electrodes.

The tilted fluid interface 15 can turn light that is transmitted through the liquid lens 10. The liquid lens 10 can have an axis 28. The axis 28 can be an axis of symmetry for at least a portion of the liquid lens 10. For example, the cavity 12 can be substantially rotationally symmetrical about the axis 28. The truncated cone portion of the cavity 12 can be substantially rotationally symmetrical about the axis 28. The axis 28 can be an optical axis of the liquid lens 10. For example, the curved and untilted fluid interface 15 can converge light towards, or diverge light away from, the axis 28. The axis 28 can be a longitudinal axis of the liquid lens 10, in some implementations. Tilting the fluid interface 15 can turn the light 30 passing through the tilted fluid interface relative to the axis 28 by an optical tilt angle 32. The light 30 that passed through the tilted fluid interface 15 can converge towards, or diverge away from, a direction that is angled by the optical tilt angle 32 relative to the direction along which the light entered the liquid lens 10. The fluid interface 15 can be tilted by physical tilt angle 34 that produces the optical tilt angle 32. The relationship between the optical tilt angle 32 and the physical tilt angle 34 depends at least in part on the indices of refraction of the fluids 14 and 16.

The optical tilt angle 32 produced by tilting the fluid interface 15 can be used by a camera system to provide optical image stabilization, off-axis focusing, etc. In some cases different voltages can be applied to the electrodes 22a-d to compensate for forces applied to the liquid lens 10 so that the liquid lens 10 maintains on-axis focusing. Voltages can be applied to control the curvature of the fluid interface 15, to produce a desired optical power or focal length, and the tilt of the fluid interface 15, to produce a desired optical tilt (e.g., an optical tilt direction and an amount of optical tilt). Accordingly, the liquid lens 10 can be used in a camera system to produce a variable focal length while simultaneously producing optical image stabilization.

Figure 5 show cross-sectional views of an example liquid lens 10. As shown, the first fluid 14 and the second fluid 16 can be seen forming a lens structure. As shown in Figure 5, the first fluid 14 may include a polar fluid and/or the second fluid 16 may include an oil (e.g., a Baltic oil).

Electrowetting Device Structures

Alternative geometrical structures for electrowetting devices (e.g., liquid lenses) can be used. Although various implementations are discussed herein in connection with liquid lenses, various other types of electrowetting devices (e.g., optical switches, shutters, displays, etc.) can use features disclosed herein. As described herein, some designs can use a cone design containing two fluids for electro wetting on a dielectric (EWOD). However, alternative designs can provide several technical advantages. First, some designs do not require that the walls be maintained with high precision smoothness. For example, roughness levels greater than about 50 nm, or other values, are possible. Moreover, such designs do not require maintaining uniform part heights. For example, the area of the cavity surface that the edge of the fluid interface moves across can be planar, which can be easier to make with high precision smoothness, as compared to a cone shaped cavity. A protrusion can be present (e.g., used for centering a fluid drop) at a location where the edge of the fluid interface does not move across in the operational range of fluid motion. Roughness, bumps, variations in coating thickness, and the like, which can be associated with the protrusion, can be tolerable without degrading the performance of the electrowetting device, because the edge of the fluid interface does not move across those areas.

In certain designs, high volume manufacturing can be done via“through hole via” drilling of a glass wafer, which can form a cone-shaped cavity. A subsequent bonding step can be performed wherein a bottom viewing window is adhered to the center cone wafer part. A top wafer cover may then also be bonded and sealed to the center cone part (e.g., hermetically). During the manufacture of certain designs, it may be desirable to provide a hydrophobic barrier coating over one or more electrodes. Coating the electrode(s) with a polymer layer can be challenging and may require special coating systems. In some cases, the cone-shaped cavity can be challenging to coat with the hydrophobic layer (e.g., parylene) with appropriate thickness uniformity and smoothness. Accordingly, some implementations disclosed herein provide alternative designs which can be easier to coat (e.g., with a hydrophobic layer). For example, some coating methods (e.g., chemical vapor deposition) may be used to substantially uniformly coat various parts of the liquid lens. However, sharp edges and/or angles may not always be uniformly coated. Certain designs disclosed herein allow for fewer sharp angles/edges and may promote more uniform coating. Moreover, certain implementations disclosed herein may be rapidly manufactured in high volume wafer format with fewer challenges in the coating process.

An electro wetting chamber that does not include a cone-shaped cavity can be employed in some implementations. For example, in some implementations, as further described herein, a raised portion (e.g., a half-ball) can be included in the electro wetting device (e.g., lens). Lens structures including the raised portion can be used in EWOD-driven focusing. In certain implementations, the electrode regions can be disposed at least partially laterally from the raised portion. At rest (e.g., in an undriven state) the nonpolar fluid, which may have the higher refractive index, can coat or otherwise cover the raised portion, which may include a hydrophobic barrier coating. When a voltage is applied to the electrodes, the polar fluid can be attracted to the surface that includes the hydrophobic coating and can displace the nonpolar fluid to move the nonpolar fluid towards (e.g., over) the raised surface, thereby creating a light focusing lens with variable curvature. The raised surface may be disposed centrally on a surface of the chamber. The fluids disclosed herein may be used in any implementations described herein.

In certain implementations, such structures may be employed in other novel optical or other types of applications such as coupled with a waveguide (e.g., from a side wall). For example, lens structures used in combination with a waveguide may be used for on-chip optical coherence tomography (OCT) and/or Raman spectroscopy. Certain combinations of waveguides and lens structures can be used to provide a dynamic coupling capability. Manufacture of some of the lenses described herein can be performed using injection molding. Injection molded optical devices can advantageously employ one or more various material compositions for various parts of the lens structures described herein (e.g., for the substrate(s)). For example, the substrates may be formed in part from glass, glass ceramic, ceramic, and/or plastics (e.g., cyclic olefin co-polymers). Moreover, the method of manufacturing the elements described herein can be done in numerous ways. For example, certain lens components can be created using wafer scale lens production procedures. Additionally or alternatively, one or more components described herein may be 3D printed. For example, arrays of such elements may be disposed on a round wafer (e.g., 6 inch or 8 inch, or any suitable size). Other variations are possible.

Certain implementations allow the actuation of a higher index fluid over a central hemisphere structure. The same or similar diopter power may be obtained with a cone geometry described herein as with a hemisphere configuration (e.g., at least about 0 diopters to about 60 diopters). The use of such a hemisphere (or other raised structure) in the lens chamber can provide various benefits. For example, lower manufacturing precision (e.g., greater than 10 nm variation) may be acceptable to allow for proper actuation of the polar fluid along the lens chamber wall of certain implementations described herein. Cone-shaped cavities can be formed in glass, and it can be challenging to manufacture sufficiently smooth and precise glass structures in a cost effective and time effective manner. Certain implementations disclosed herein can use glass and/or injection molded plastics, which may be more forgiving for yielding a functional lens or other electrowetting device. Portions of the electro wetting cavity that contact the fluid interface edge can be formed with sufficient smoothness (e.g., surface roughness of less than about 100 nm, about 90 nm, about 80 nm, about 70 nm, about 60 nm, about 50 nm, about 40 nm, about 30 nm, about 25 nm, about 20 nm, about 15 nm, about 10 nm or less) more readily when no cone-shaped cavity is used (e.g., in implementations having a hemisphere protrusion). The portions of the electrowetting cavity that contact the fluid interface edge (e.g., across the range of motion for the fluid interface) can be substantially planar.

As noted, same or similar optical power may be obtained using a cone geometry as with a modified (e.g., hemisphere) geometry, as disclosed herein. Additionally, because sharp edges can be difficult to coat (e.g., using a liquid-based precursor polymer barrier film), the modified structures can provide for more uniform thickness in the polymer coating, as compared to cone-shaped cavities. The modified lens structure (e.g., hemisphere structure) can provide a central point for raising the nonpolar fluid. Such a structure can provide an anchor and/or support to the fluids. The raised portion (e.g., hemisphere structure) can provide a centering function for the fluid (e.g., the non-polar fluid). In certain implementations, the one or more electrodes may be planar and/or may at least partially surround the raised portion (e.g., hemisphere). The planar shape, and the resulting smoothness, of the area that the fluid interface moves across can reduce hysteresis in the electro wetting device.

Certain laser-based techniques may be used in the manufacturing of the raised (e.g., hemisphere) structures disclosed herein. Such techniques can allow for the manufacture of raised structures that can be made smaller, in some cases, than a cone-shaped cavity. The raised structures can have a diameter or width of about 10 microns, about 7 microns, about 5 microns, about 3 microns, about 2 microns, about 1.5 microns, about 1 micron, 0.5 microns, or any values therebetween, or any ranges bounded therein, although other sizes can be used). The height of the raised structure can have a height of about 10 microns, about 7 microns, about 5 microns, about 3 microns, about 2 microns, about 1.5 microns, about 1 micron, about 0.5 microns, or any values therebetween, or any ranges bounded therein, although other sizes can be used. The structures disclosed herein may be well suited for filling even such small structures with fluid. Some structures disclosed herein may be easier to fill (e.g., with the nonpolar fluid and/or the polar fluid) during the assembly process, as compared to positioning fluid in a cone-shaped cavity of comparable size.

In certain implementations, light may be coupled (e.g., through a sidewall) into the electrowehing structures described herein. The light may be incident on computer chips. Certain implementations may allow for the use of lens arrays to be used in directing multiple beams of light or larger beam sets. For example, a single cavity can include multiple raised portions (hemispheres), and electrodes arranged to make a plurality of variable focus fluid lenses in a single cavity. Either or both of the fluids (e.g., the nonpolar fluid) could be colored to produce an optical filter lens. The electrowehing device could be used as a shuher. For example, one of the fluids (e.g., the nonpolar fluid can be opaque). Additionally or alternatively, a display (e.g., a reflective display) may be made using electrowehing devices disclosed herein, such as by coloring the plurality of nonpolar fluids (e.g., red/green/blue or cyan/yellow/magenta) in a plurality of electro wetting devices. A plurality of raised surfaces (e.g., hemispheres) can be incorporated into the lens structure to be used, for example, for lighting (e.g., by putting hemispheres in an array). Directional lighting systems can use the fluid interface (or array of fluid interfaces) to control the direction of light, such as from a light-emitting diode (LED) or organic light-emitting diode (OLED). The electrowetting devices can be used for back lighting (e.g., for displays) and may be used in combination with other implementations disclosed herein.

Figure 6A shows an example implementation of an electrowetting device (e.g., a liquid lens) structure 10. Many features of the electrowetting device 10 of Figure 6A can be similar to the implementations of Figures 1-4. While the term“lens” is often used to describe the device 10, other uses are also possible, as described herein. In Figure 6A, a plurality of states of the fluids are shown simultaneously (e.g., superimposed). As shown, a liquid lens 10 can include a cavity or chamber 12. The cavity 12 can be bounded by a plurality of surfaces. For example, the cavity 12 can be bounded by a base surface 47 on one end (e.g., a bottom in the orientation of Figure 6A, although in many uses the electrowetting device can be positioned at any suitable orientation). A first electrode 22 can be disposed on an opposite side of the base surface 47 from the fluids 14, 16. The first electrode 22 can be insulated from the fluids 14 and 16, such as by insulating material 24 (e.g., a parylene layer). The one or more electrodes 22 can be a transparent electrode(s). The electrode(s) 22 can include indium tin oxide (ITO). On an opposing end, the cavity 12 (e.g., the top in the orientation of Figure 6A) can be bounded by a second electrode 26. The second electrode 26 may be in electrical communication with the first fluid 14. The electrode 26 can be a transparent electrode. The electrode 26 can include indium tin oxide (ITO). In some implementations, the electrode 26 can extend across the cavity 12. In some implementations, the electrode 26 does not extend across the cavity. For example, the electrode 26 can be flush with the sidewall 44 and have electrical contact with the fluid 14. Other features of the elements of the cavity 12 and other aspects of the liquid lens 10 may be described elsewhere herein and need not be repeated here.

The base surface 47 may be adjacent one or more sidewalls 44. The base surface 47 and the one or more sidewalls 44 may form an interior comprising substantially one or more volumes. For example, a cross section taken transvers to the axis 28 can have a cross-sectional shape of a rectangle, square, hexagon, circle, etc. Other volume shapes may be defined generally by the base surface 47 and the one or more sidewalls 44. The one or more sidewalls 44 can be formed of an insulating material. The sidewalls 44 can be glass, in some cases. The sidewalls 44 can be less hydrophobic than the base surface 47. In some implementations, the one or more sidewalls 44 are formed of hydrophilic material and/or coated with the same. The one or more sidewalls 44 can be disposed adjacent at least a portion of the second electrode 26. The second electrode 26 may span from a first side of the cavity 12 to the opposite side. The second electrode 26 can be substantially transparent so as to allow light to transmit therethrough. Additionally or alternatively, the second electrode 26 may form an aperture (not shown) to promote the transmission of light therethrough (e.g., along the optical axis 28). An upper window 20 can be disposed on an opposite side of the second electrode 26 as the cavity 12. The upper window 20 may be disposed adjacent the second electrode 26 in some implementations. The second electrode 26 may include one or more electrodes. Additionally or alternatively, the first electrode 22 can include one or more electrodes, as described elsewhere herein. A lower window 18 may be disposed opposite the cavity 12 and/or adjacent the first electrode 22, for example as shown. The upper window 20 and/or lower window 18 can include one or more materials, such as glass, ceramic, plastic, or any other suitable material described herein. The upper window 20 and/or lower window 18 may be formed using injection molding or some other molding process, milled, 3D printed, formed using a deposition (e.g., chemical vapor deposition) process, or using some other method.

The base surface 47 can have a planar portion that can be interrupted by one or more raised surfaces 48. Figure 6A illustrates a single raised surface 48, although some implementations can include multiple raised surface (e.g., to produce a plurality of variable focus liquid lenses). The raised surfaces 48 can be patterned across the base surface 47 in an array or any other suitable pattern. Each raised surface 48 may have one or more attributes described herein. Each raised surface 48 can have one or more electrodes 22, which can be insulated from electrodes 22 associated with other raised surfaces 48. The electrodes 22 can be driven independently to form independently controlled liquid lenses (e.g., within a single cavity). For clarity and succinctness, the one or more raised surfaces 48 will be referenced in the singular. The raised surface 48 can be disposed adjacent the base surface 47, for example as shown. The base surface 47 may include a coating of a hydrophobic and/or insulating material. The material may include parylene. The base surface

47 can at least partially or even completely surround the raised surface 48. The raised surface

48 may be disposed to at least partially intersect the axis 28 (e.g., optical axis, axis of symmetry, etc.). For example, the raised surface 48 may be substantially centered about the axis 28 and/or centered within the cavity 12 along the base surface 47. The base surface 47 may be substantially flat. The raised surface 48 can be flat but may instead by curved, for example as shown. The raised surface 48 can include a coating or other material that is hydrophobic and/or insulating. For example, parylene may be included on the raised surface 48. The raised surface 48 and the base surface 47 may include the same coating and/or other material. A transition between the base surface 47 and the raised surface 48 may be abrupt, but in some implementations, is smooth.

The raised surface 48 may be disposed on a raised portion 40. The raised portion 40 may be an optically transmissive (e.g., transparent) material. In some implementations the raised portion 40 shares material of the lower window 18. For example, the raised portion 40 may be molded or otherwise integrally formed with the lower window 18. The contour of the raised surface 48 may share and/or be dictated by the contour of the raised portion 40. In some implementations, the raised portion 40 is molded and/or formed (e.g., using a deposition process, such as one described herein) onto the base surface 47. Chemical vapor deposition may be used to form the raised portion 40 and/or the raised surface 48. In some implementations, the raised surface 48 is merely the outer surface of the raised portion 40.

The raised surface 48 and/or the raised portion 40 may take a variety of shapes. While the raised portion 40 will be described, any shape, contour, or feature described with respect to the raised portion 40 may similarly apply to the raised surface 48. The raised portion 40 can have a curved profile, such as a portion of a sphere. For example, the raised portion 40 can be a hemisphere or half-ball. A truncated sphere may be used (e.g., less than or greater than half a sphere). In some implementations, other shapes can be used. For example, the raised portion 40 can be an ovoid (or portion thereof). The raised portion 40 may be an ellipsoid (or portion thereof). A cross-section of the raised portion 40 may define a surface and/or profile that may be obtained by taking a cross-section of a cone (e.g., a circle, an ellipse, a parabola, hyperbola, etc.). Other profiles may be used, such as a Gaussian curve or other curve. The raised portion 40 can exemplify substantial radial symmetry about an axis 28, such as the optical axis. The raised portion 40 may be configured to apply optical power to light incident thereon.

The raised portion 40 can have a height (e.g., as measured along the axis 28 from the base surface 47) greater than a height of the insulating/hydrophobic layer 24. The height of the raised portion 40 may be less than half a height of the cavity 12. The height of the raised portion 40 can be about 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, or 0.45 times the height of the cavity 12, or any height between any value therein or fall within a range defined by any value therein. The height of the raised portion 40 may be defined at a center of the raised portion 40 (e.g., along the axis 28). The raised portion 40 can have a width and/or a height of about 10 microns, about 7 microns, about 5 microns, about 3 microns, about 2 microns, about 1.5 microns, about 1 micron, 0.5 microns, or any values therebetween, or any ranges bounded therein, although other sizes can be used. The raised portion 40 may provide an optical power of 0.1, 2, 5, 10, 15, 20, 25, 30, 35, 40, 50, or 60 diopters, any optical power within those values or within any range created by any of those values. However, in some implementations the fluids are chosen and/or other features are included (see, e.g., Figure 6B) such that no optical power is provided by the raised portion 40.

The first one or more electrodes 22 can define an aperture 56 through which light may pass. The aperture 56 may be any shape (e.g., an ellipse, a hexagon, a rectangle). The shape may be regular or irregular. The aperture 56 may be formed of any optically transmissive material and/or may be the same material and/or element as the lower window 18 and/or the raised portion 40. The aperture 56 can be disposed so as to intersect the axis 28. For example, the aperture 56 may be centered about the optical axis 28. The aperture 56 can exemplify complete or partial radial symmetry. As shown in Figure 6A, in some implementations the raised portion 40 may be disposed directly above (e.g., along the optical axis 28) the aperture 56.

A level of the second fluid 16 may be such that in an undriven state the second fluid 16 does not create a substantially horizontal fluid interface 15, such as is shown in Figure 6A. In an undriven state, the wetting properties of the raised surface 48 (e.g., the hydrophobic layer 24) can cause the second fluid 16 to cover the raised portion. In the undriven state, the fluid interface can have a curved center portion (as shown in Figure 7A). However, in some implementations sufficient second fluid 16 is provided to allow a level of the second fluid 16 be horizontal and/or higher than a height of the raised surface 48 in an undriven state of the liquid lens 10 (as shown in Figure 7F).

Figure 6B shows the liquid lens 10 of Figure 6A with a compensating feature 42. The compensating feature 42 can be included to reduce and/or substantially offset an optical power provided by the raised portion 40. The compensating feature 42 may include a recess. For example, a portion of material can be removed from the lower window 18. The compensating feature 42 can take a shape substantially identical to the shape of the raised portion 40. In some cases, the curvature of the compensating feature 42 can be different than the curvature of the raised portion 40, such as to account for the different indices of refraction of the materials that border the raised portion 40 (e.g., the second fluid, such as oil) and the compensating features (e.g., air). The compensating feature 42 may be disposed along the same axis (e.g., the optical axis 28) as the raised surface 48. The compensating feature 42 may be disposed elsewhere in the liquid lens 10. For example, the compensating feature 42 may be disposed in the upper window 20. Other variations are possible.

Figures 7A - 7E show the liquid lens 10 of Figure 6A in individual states. Figure 7A shows the liquid lens 10 in an undriven state. In some cases, in the undriven state, the second fluid 16 coats substantially all of the base surface 47 and the raised surface 48. As shown, a height of the second fluid 16 above the base surface 47 can be lower than the height of the raised surface 48. However, as disclosed herein, other variations are possible. As shown, the second fluid 16 may form a convex interface against the one or more sidewalls 44. This may be because the one or more sidewalls 44 are hydrophilic (e.g., or less hydrophobic than the base surface 47). However, other variations are possible. For example, the interface of the second fluid 16 with the one or more sidewalls 44 may be concave, such as if the one or more sidewalls 44 includes a hydrophobic material.

Figures 7B - 7E show the example liquid lens 10 in a variety of driven states. As shown, the more the one or more electrodes of the first electrode 22 are driven, the more bulbous the shape of the second fluid 16 may become. As shown, the second fluid 16 may form a shape substantially symmetric about the raised surface 48. In some implementations, as a voltage (e.g., an RMS voltage) differential is increased from the undriven state, the curvature of the shape of the fluid interface can initially decrease and can then increase. For example, in the undriven state the raised portion 40 can produce a curvature in the fluid interface (e.g., Figure 7A). As the voltage is increased and the fluid interface transitions from the state of Figure 7A to 7B, the curvature of the fluid interface can decrease. For example, more of the second fluid 16 can be pushed into the area of the raised portion 40. With reference to Figure 7C, as the voltage is increased and additional second fluid 16 is pushed into the area of the raised portion, at some point the fluid interface can become substantially independent of the raised portion 40. The fluid interface can“lift” off of the raised portion and the curvature of the fluid interface can increase as additional voltage is applied (e.g., see Figures 7C to 7E). Thus, in some cases the optical power of the liquid lens 10 can initially decrease as voltage is applied (e.g., in a first operating stage). As the voltage increases, the liquid lens 10 can transition to a second operating stage, where the optical power of the liquid lens increases as the voltage increases.

Figure 7F shows an example implementation of a liquid lens 10 with enough of the second fluid 16 in the cavity 12 so that the second fluid 16 can cover the raised portion 40 when the fluid interface is substantially flat. In some cases, the undriven state can be substantially flat, such as at a central imaging portion of the fluid interface that is used to produce an image, as shown in Figure 7F. In some cases, the edges can curve down toward the base surface 47, as discussed herein. In some cases, the raised portion 40 can impede the central portion of the fluid interface from sagging.

As shown in Figures 7A to 7E, the edge of the fluid interface can move across the base surface 47 for the range of motion, which can be dictated by the wetting properties of the cavity surfaces, the positions of the electrodes, and/or the voltages applied. The base surface 47 can be substantially planar (e.g., substantially flat) across the range of motion for the edge of the fluid interface. The base surface 47 across the range of motion can have a surface roughness of less than about 100 nm, about 90 nm, about 80 nm, about 70 nm, about 60 nm, about 50 nm, about 40 nm, about 30 nm, about 25 nm, about 20 nm, about 15 nm, about 10 nm or less. Manufacturing a smooth surface can be easier for a substantially planar surface, such as the base surface 47, than for a curved surface, a comer, or an angle, which can be present in a cone-shaped recess. The smoothness of the surface across the range of motion can reduce hysteresis for the electro wetting device 10. The substantially planar surface can simplify manufacturing of the device 10, such as the coating of the insulating or hydrophobic layer 24.

The raised portion 40 can facilitate positioning (e.g., centering) of the second fluid 16 in the cavity 12. The raised portion 40, in some implementations, can impede sagging of the fluid interface (e.g., at an undriven state or a relatively low voltage state). The raised portion 40 can also reduce the volume of the second fluid 16 in the electrowetting device 10. The raised portion can be outside the range of motion for the edge of the fluid interface. Accordingly, roughness, bumps, nonuniform coating thicknesses, etc. that can result at or near the raised portion 40 can have little or no effect on the fluid interface as it moves across the range of motion. In some cases, the transition from base surface 47 to the raised portion 40 can be smooth or rounded, so that when coated the coating can be more uniform than if the transition were a hard edge. The raised portion 40 can be manufactured using many suitable methods. A laser can be used to raise up a protrusion (e.g., a microlens or hemisphere) on glass. Lithography can be used to pattern cubic structures and then melt them into the glass. Injection molded plastics and/or hot embossing can also be used to form wafer based raised portions (e.g., hemisphere lenses). Glass molding can also be used to shape the protrusion (e.g., hemisphere structure). Sol gel methods can be used to make the raised portion 40. 3D printing and inkjet deposition can also be deployed to manufacture the raised portion(s) (e.g., the lens and/or lens arrays). Photopolymerization of polymers can also be used. The radius of the hemisphere lens, the height of the raised portion, and/or the half-width of the raised portion, can be about 0.5 microns, about 1 micron, about 1.5 microns, about 2 microns, about 3 microns, about 5 microns, about 7 microns, about 10 microns, about 15 microns, about 25 microns, about 50 microns, about 100 microns, about 200 microns, about 300 microns, about 500 microns, about 750 microns, about 1 mm, about 1.5 mm, about 2 mm, about 2.5 mm, about 3 mm, about 4 mm, about 5mm, or any values therebetween, and/or any ranges bounded by these values. The figures are not necessarily drawn to scale, but the dimensions and proportions are intended to form part of the this disclosure. Once the raised portion (e.g., 3D hemisphere) is constructed on the substrate, one can then use photolithography to establish a blocking mask to then deposite the electrode(s) 22 and dielectric and/or hydrophobic barrier film(s) 24.

Figures 8A - 8F show a variety of top views (e.g., along the optical axis 28) of example configurations of the first electrodes 22. Each of the electrodes may be photolithographically patterned, for example. The electrodes may at least partially or completely surround the raised portion 40 of a liquid lens 10. Each electrode may be driven simultaneously or they may be driven individually or in concert with other electrodes (e.g., sequentially). Figure 8A shows an example implementation having four electrodes 22a, 22b, 22c, 22d. As shown, the four electrodes 22a, 22b, 22c, 22d form quadrants about the raised portion 40 and/or the aperture 56. Each electrode may be insulated from neighboring electrodes by an insulator 46. The insulator 46 may be a gap between adjacent electrodes 22 filled by insulation material 24 (e.g., by forming the gap and then depositing the insulation material 24 to the electrodes 22 and the gap) or by another insulating material. As shown, the insulator 46 forms a substantially straight line. The straight line may run from an edge of the liquid lens 10 cavity 12 to an edge of the aperture 56. In some implementations, subsequent insulators 46 do not intersect. However, intersecting implementations are possible. Figure 8B shows an example configuration of eight electrodes disposed radially about the raised portion 40 (though they may be axially offset from (e.g., lower than) the raised portion raised surface 48). As shown in Figures 8A and 8B, the plurality of electrodes 22 may generally form a square. The cavity 12 can have a generally square cross-sectional shape. Other shapes are possible. For example, Figures 8C - 8D show additional configurations of the first electrodes 22 and/or cavity 12 that generally form a circle.

Figures 8E - 8F show other configurations of the first electrodes 22 (e.g., driving electrodes). As shown, the insulator 46 may include a plurality of segments (e.g., straight segments) that intersect with neighboring segments at an angle. Accordingly, such insulators 46 may form a non-linear pattern. For example, as shown, the insulators 46 may each form a zig-zag pattern. This pattern can create“fingers” between neighboring electrodes 22. The fingers can promote better control of the fluids when driving them for use in the liquid lens 10. The pattern shown can provide a better distributed field effect than some alternatives. While two example configurations have been shown in Figures 8E - 8F, these examples are by no means limiting. The driving electrodes 22 can be interdigitated electrodes. One or more portions of a first electrode 22 can be positioned between portions of an adjacent electrode 22. Various different electrode shapes and/or insulator 46 shapes can be used. For example, the insulators 46 or electrode 22 edges can be curved, or S- shaped, in some cases. The liquid lens of Figures 1 - 4 can have interdigitated electrodes, such as the example electrodes in Figures 8E - 8F.

The electro wetting device (e.g., liquid lens 10) structures that have been disclosed herein can be used in a variety of advantageous optical elements. For example, an electro wetting device (which can have features similar to any of the liquid lens 10 embodiments disclosed herein) may be used in combination with a waveguide and/or an optical sensor, or other optical device, to obtain additional functionality. For example, Figures 9A - 9C show example implementations of an optical device 50 that includes a waveguide 52 in optical communication with an electrowetting device 10. The electro wetting device 10 can be used for electrically addressed optical computer interconnects, for example. An optical waveguide 52 can be used to direct light into the cavity of the electro wetting device 10, such as in from the sides (e.g., through the sidewall). Light can propogate through the waveguide 52 by total internal reflection, for example. The wave guide can be an optical fiber. The optical device 50 may also include an optical component 58. The optical component 58 can be an optical sensor, an optical interconnect, another waveguide, a waveguide light input element, etc. The optical component 58 may be disposed within or adjacent the electro wetting device 10. The optical component 58 can include a computer optical chip. The electrowetting device 10 can be used for activated optical coupling with a light waveguide 52 for optical chip interfaces. The electrowetting device 10 can operate as an optical switch or optical coupling for any suitable appliation or system.

Figure 9A shows the electrowetting device 10 of the optical device 50 in an undriven state. The waveguide 52 may be configured to couple light into the electro wetting device 10, such as into the first fluid (e.g., the polar fluid). As shown, the waveguide 52 can couple the light into a side (e.g., through the one or more sidewalls 44) of the electro wetting device 10. In some implementations, the waveguide 52 is butt coupled to the electro wetting device 10, for example as shown. However, other configurations are possible. For example, the waveguide 52 may couple the light into the electro wetting device 10 via an optical fiber or through another optical medium. When the fluid interface 15 is at a first position (e.g., in an undriven state, such as can be seen in Figure 9A), the light from the waveguide is not coupled onto the optical component 58. For example, light from the waveguide 52 can propagate through the first fluid without contacting the second fluid or the fluid interface.

As shown in Figure 9A, the light 30 may be coupled into the electro wetting device 10, for example, parallel to the base surface 47 and/or perpendicular to the one or more sidewalls 44. Because the electrowetting device 10 of the optical device 50 is in an undriven state as shown, the light 30 can pass to the opposite side of the electrowetting device 10 without encountering the second fluid 16. The light may pass instead just through the first fluid 14 and therefore not be deflected. Thus, the optical component 58 may receive little or no light 30 from the waveguide in a first state (e.g., the undriven state), depending on the position of the optical component 58.

Figure 9B shows the optical turning element 50 in a first driven state. In the first driven state, the fluid interface 15 may form a convex shape, such as described elsewhere herein. The fluid interface 15 may be positioned such that the light 30 from the waveguide 52 impinges on the fluid interface 15 and/or the second fluid 16. Accordingly, the light 30 may be redirected by the fluid interface 15. The redirected light 54 may be refracted and/or reflected (e.g., by total internal reflection (TIR)) toward the optical component 58. In appropriate implementations, some of the redirected light 54 may be refracted or focused by the raised portion 40. In this way, some light may be affected by both the fluid interface 15 and the raised portion 40. The light that is redirected (e.g., focused) by the raised portion 40 may provide important information about the incoupled light 30 and/or about the fluid interface 15.

Figure 9C shows the optical device 50 with the electrowetting device 10 in another driven state. The fluid interface 15 can be tilted so that the light 30 from the waveguide 52 may be input directly into the second fluid. The light can be reflected (e.g., by total internal reflection (TIR)) by the fluid interface 15 toward the optical component 58. Some of the deflected light 54 may be further refracted (e.g., focused) by the raised portion 40 in some implementations. Again, such light that is refracted (e.g., focused) by the raised portion 40 may provide helpful information to the optical component 58. The optical component 58 can include an array of couplers configured to detect the light incident thereon. The fluid interface can be used as a turning feature for redirecting light. While the example implementations of Figure 9A - 9C include a raised portion 40, other implementations can omit the raised portion 40. For example, the electrowetting device of Figures 9A - 9C can be any implementation of Figures 1 - 4.

The optical device 50 can be used as an optical switch. For example, the state of Figure 9A can be an off state, and light is not coupled from the waveguide to the optical component 58. The state of either Figure 9B or 9C can be an on state, and light from the waveguide can be coupled to the optical component 58. In some implementations, the optical device 50 can be a sensor, which can determine a position of fluid interface 15. The information about light received by the optical component 58 (e.g., an optical sensor) may be transmitted to a controller and/or processor (not shown), which may determine a position of the fluid interface 15 based on that information.

With the interface 15 in a first position, the device 10 can be configured to deliver light from an input to an output, and with the interface 15 in a second position, the device 10 can be configured to impede light from propagating from the input to the output. The input can deliver light into the cavity, such as from a waveguide 52. The output can be a waveguide, an optical sensor, or a sample, etc. or an optical collector which can collect received light to be delivered to another component.

In some cases, the fluid interface can turn light received from the input (e.g., in order to deliver the turned light to the output). The device 10 can be configured to turn the light by about 5 degrees, about 10 degrees, about 15 degrees, about 30 degrees, about 45 degrees, about 60 degrees, about 75 degrees, about 80 degrees, about 85 degrees, about 90 degrees, about 95 degrees, about 100 degrees, about 105 degrees, about 120 degrees, or any values or ranges therebetween, although any suitable turning angles can be used. The light can be turned by reflection (e.g., total internal reflection) at the interface 15. The light can be turned by refraction at the interface 15. The interface 15 can be flat, planar, or curved. In some cases, the interface 15 can focus or defocus the light with optical power. The electro wetting device 10 can be a liquid lens in some cases. The interface 15 can be tilted, as discussed herein, to transition between the first and second positions. The interface 15 curvature can change, as discussed herein, to transition between the first and second positions.

Many variations are possible. The inlet and the outlet can be aligned, so that light can propagate directly from the input to the output, such as without impinging on the interface 15, such as when the optical switch is in an on state. The off state can move the interface 15 to turn the light, or otherwise impede the light from reaching the output. The waveguide 52 can input the light into either the first fluid or the second fluid. The device 10 can tilt the interface 15 in the opposite direction of that shown in Figure 9C, in some cases, so that the light is input into the same fluid (e.g., the first fluid) in both the first (e.g., on) state and the second (e.g., off) state. In some embodiments, one of the fluids can be opaque. For example, in an implementation similar to Figures 9A to 9C, the lower fluid can be opaque. In a state similar to Figure 9A, the light can propagate directly from the input to the output (e.g., through the upper fluid). The output can be positioned across from the waveguide 52, for example. In a state similar to Figures 9B or 9C, the opaque material can block the light from reaching the output. The device can be configured, such as with hydrophobic materials, such that either the state of 9A or the state of 9B is the undriven state, and the other of Figures 9B and 9A is the driven state.

Figure 10 shows an example implementation of an optical device 50 with an array of optical couplers that can include raised portions. Electrodes (not shown in Figure 10) can be driven independently to selectively coupled light from the plurality of electrodes onto one or more corresponding optical components.

Figure 11 shows an example implementation of an electro wetting device 10 that can produce multiple fluid interfaces (e.g., arranged in an array). A single cavity can include multiple raised portions 40, which can be arranged in an array. Electrodes 22 can be driven independently to produce different fluid interfaces for the different raised portions 40. The electrodes 22 can have interdigitated edges, similar to the disclosure of Figures 8E - 8F, in some cases.

Example Implementations

A number of example implementations described herein are provided below:

In a lst example, a liquid lens includes: a chamber comprising: a substantially planar surface; and a raised surface surrounded at least in part by the substantially planar surface and disposed on an optical axis of the liquid lens; a first fluid contained in the chamber; a second fluid contained in the chamber, wherein an interface is between the first fluid and the second fluid; one or more electrodes that are insulated from the first and second fluids; and one or more electrodes in electrical communication with the first fluid, wherein the liquid lens is configured such that a position of the interface is based at least in part on voltages applied between the one or more insulated electrodes and the one or more electrodes in electrical communication with the first fluid.

In a 2nd example, the liquid lens of example 1, wherein the raised surface is surrounded completely by the substantially planar surface.

In a 3rd example, the liquid lens of any one of examples 1 to 2, wherein the raised surface comprises a rounded bulge.

In a 4th example, the liquid lens of example 5, wherein the rounded bulge comprises a portion of a sphere.

In a 5th example, the liquid lens of example 5, wherein a cross-section of the rounded bulge comprises a surface obtained from a cross-section of a cone

In a 6th example, the liquid lens of example 5, wherein the rounded bulge has a Gaussian shape.

In a 7th example, the liquid lens of any one of examples 1 to 6, wherein the raised surface comprises a hydrophobic material.

In a 8th example, the liquid lens system of example 8, wherein the hydrophobic material comprises parylene.

In a 9th example, the liquid lens of any one of examples 1 to 8, wherein the chamber comprises: a sidewall; and a base comprising the substantially planar surface and the raised surface. In a lOth example, the liquid lens of any one of examples 1 to 9, wherein the one or more electrodes that are insulated from the first and second fluids form an aperture.

In a l lth example, the liquid lens of example 10, wherein the aperture is disposed on the optical axis.

In a l2th example, the liquid lens of any one of examples 1 to 11, wherein an edge of the interface has a range of motion that is contained within the substantially planar surface.

In a l3th example, the liquid lens of any one of examples 1 to 12, wherein the raised surface supplies an optical power to light along the optical axis.

In a l4th example, the liquid lens of example 13, further comprising a compensating optical feature, the compensating optical feature that provides an optical power that at least partially counters the optical power provided by the raised surface.

In a l5th example, the liquid lens of example 14, wherein the compensating optical feature comprises an indentation in the liquid lens.

In a l6th example, the liquid lens of any one of examples 1 to 15, wherein the one or more insulated electrodes comprises four insulated electrodes positioned at four quadrants of the liquid lens.

In a l7th example, the liquid lens of any one of examples 1 to 16, wherein the one or more insulated electrodes are disposed along a plane substantially parallel to the substantially planar surface.

In a 18th example, the liquid lens of any one of examples 1 to 17, wherein a level of the second fluid exceeds a height of the raised surface when the interface is substantially flat.

In a l9th example, the liquid lens of any one of examples 1 to 18, further comprising a transparent substrate adjacent the one or more electrodes that are insulated from the first and second fluids.

In a 20th example, the liquid lens of any one of examples 1 to 19, wherein the one or more electrodes in electrical communication with the first fluid transmit light therethrough.

In a 21 st example, an electrowetting device comprising: a chamber comprising: a sidewall; a flat surface adjacent the sidewall; a curved protrusion surrounded at least in part by the flat surface; a first fluid contained in the chamber; and a second fluid contained in the chamber, wherein an interface is between the first fluid and the second fluid, wherein the wetting properties of the chamber position the second fluid centered on the curved protrusion.

In a 22nd example, the electro wetting device of example 21, wherein the curved protrusion lies on an optical axis of the electrowetting device.

In a 23rd example, the electro wetting device of any one of examples 21 to 22, further comprising: one or more electrodes that are insulated from the first and second fluids; and one or more electrodes in electrical communication with the first fluid, wherein the electrowetting device is configured such that a position of the interface is based at least in part on voltages applied between the one or more insulated electrodes and the one or more electrodes in electrical communication with the first fluid.

In a 24th example, the electrowetting device of any of examples 21 to 23, wherein the curved protrusion is surrounded completely by the flat surface.

In a 25 th example, the electro wetting device of any one of examples 21 to

24, wherein the electrowetting device is a liquid lens.

In a 26th example, the electro wetting device of any one of examples 21 to

25, wherein the curved protrusion is raised relative to the flat surface.

In a 27th example, the electrowetting device of any one of examples 21 to

26, wherein the curved protrusion comprises a portion of a sphere.

In a 28th example, the electro wetting device of any one of examples 21 to 26, wherein the curved protrusion comprises a portion of an ovoid.

In a 29th example, the electro wetting device of any one of examples 21 to 26, wherein a cross-section of the curved protrusion comprises a surface obtained from a cross-section of a cone.

In a 30th example, the electrowetting device of any one of examples 21 to 29, wherein the curved protrusion comprises a hydrophobic material.

In a 31 st example, the electrowetting device system of example 30, wherein the hydrophobic material comprises parylene.

In a 32nd example, the electro wetting device of any one of examples 21 to 31, wherein the curved protrusion comprises a hemisphere.

In a 33rd example, the electrowetting device of example 23, wherein the one or more electrodes that are insulated from the first and second fluids form an aperture. In a 34th example, the electro wetting device of example 33, wherein the aperture is disposed on an optical axis of the electrowetting device.

In a 35th example, the electro wetting device of example 34, wherein the curved protrusion supplies an optical power to light along the optical axis.

In a 36th example, the electrowetting device of any of examples 21 to 35, further comprising a compensating optical feature that provides an optical power substantially opposite a power provided by the curved protrusion.

In a 37th example, the electro wetting device of example 36, wherein the compensating optical feature comprises an indentation in the electrowetting device.

In a 38th example, the electrowetting device of any one of examples 23 or 33 to 34, wherein the one or more insulated electrodes comprises four insulated electrodes positioned at four quadrants of the electrowetting device.

In a 39th example, the electrowetting device of any one of examples 23 or 33 to 35, wherein the one or more insulated electrodes are disposed along a plane substantially parallel to the flat surface.

In a 40th example, the electro wetting device of any one of examples 21 to

39, wherein a fill level of the second fluid in an undriven state exceeds a height of the curved protrusion.

In a 41 st example, the electro wetting device of any one of examples 21 to

40, wherein the interface has a range of motion, and wherein an edge of the interface is disposed on the flat surface across the full range of motion for the interface.

In a 42nd example, the electro wetting device of any one of examples 21 to

41, comprising first and second interdigitated electrodes.

In a 43rd example, an electrowetting device comprising: a chamber; a first fluid contained in the chamber; a second fluid contained in the chamber, wherein an interface is between the first fluid and the second fluid; a plurality of insulated electrodes that are insulated from the first and second fluids, wherein a boundary between adjacent insulated electrodes is nonlinear; and one or more electrodes in electrical communication with the first fluid, wherein the electrowetting device is configured such that a position of the interface is based at least in part on voltages applied between the one or more insulated electrodes and the one or more electrodes in electrical communication with the first fluid. In a 44th example, the electro wetting device of example 43, wherein the boundary between adjacent insulated electrodes comprises a plurality of segment pairs, each segment pair forming an angle therebetween.

In a 45th example, the electrowetting device of any of examples 43 to 44, wherein the boundary between the adjacent insulated electrodes forms a zig-zag pattern.

In a 46th example, the electrowetting device of any of examples 43 to 45, wherein the boundary between the adjacent insulating electrodes has a curved shape.

In a 47th example, the electrowetting device of any of examples 43 to 46, wherein the plurality of insulated electrodes comprises interdigitated electrodes.

In a 48th example, an optical device comprising: a chamber comprising a base surface; a first fluid contained in the chamber; a second fluid contained in the chamber, wherein an interface is between the first fluid and the second fluid; one or more electrodes that are insulated from the first and second fluids; one or more electrodes in electrical communication with the first fluid, wherein the optical device is configured such that a position of the interface is based at least in part on voltages applied between the one or more insulated electrodes and the one or more electrodes in electrical communication with the first fluid; and a waveguide configured to couple light into the chamber.

In a 49th example, the optical device of example 48, wherein the waveguide is butt coupled to the chamber.

In a 50th example, the optical device of any of examples 48 to 49, wherein the waveguide is configured to couple the light into the chamber substantially parallel to the base surface.

In a 51 st example, the optical device of any of examples 48 to 50, wherein an amount of the first fluid is substantially equal to an amount of the second fluid in the chamber.

In a 52nd example, the optical device of any of examples 48 to 51, wherein the base surface is substantially transparent.

In a 53rd example, the optical device of any of examples 48 to 52, wherein the one or more electrodes can produce a driven state and an undriven state of the two fluids.

In a 54th example, the optical device of example 53, wherein in the undriven state, light from the waveguide is not redirected towards the base surface, and in the driven state, light from the waveguide is redirected toward the base surface. In a 55th example, the optical device of any of examples 48 to 54, further comprising a coupler array configured to detect coupled light through the base surface.

In a 56th example, the optical device of any of examples 48 to 55, wherein the base surface comprises a raised surface surrounded at least in part by a substantially flat surface.

In a 57th example, the optical device of example 56, wherein the raised surface is surrounded completely by the substantially flat surface.

In a 58th example, the optical device of any one of examples 56 to 57, wherein the raised surface comprises a plurality of curved protrusions.

In a 59th example, the optical device of any one of examples 56 to 58, wherein the raised surface is raised relative to the substantially flat surface.

In a 60th example, the optical device of any one of examples 56 to 59, wherein the raised surface comprises a rounded bulge.

In a 61 st example, the optical device of example 60, wherein the rounded bulge comprises a portion of a sphere.

In a 62nd example, the optical device of example 60, wherein a cross- section of the rounded bulge comprises a surface obtained from a cross-section of a cone or a surface having Gaussian curve.

In a 63rd example, the optical device of any one of examples 56 to 62, wherein the raised surface comprises a hydrophobic material.

In a 64th example, the device system of example 63, wherein the hydrophobic material comprises parylene.

In a 65th example, the optical device of any one of examples 56 to 64, wherein the one or more electrodes that are insulated from the first and second fluids form an aperture.

In a 66th example, the optical device of example 65, wherein the aperture is disposed about an axis perpendicular to the base surface.

In a 67th example, the optical device of any one of examples 56 to 66, wherein the raised surface supplies an optical power to light transmitted therethrough.

In a 68th example, the optical device of any of examples 56 to 67, further comprising a compensating optical feature that provides an optical power substantially opposite the optical power provided by the raised surface. In a 69th example, the optical device of example 68, wherein the compensating optical feature comprises an indentation in the optical turning feature.

In a 70th example, the optical device of any one of examples 56 to 69, wherein the one or more insulated electrodes comprises four insulated electrodes positioned at four quadrants of the optical turning feature.

In a 71 st example, the optical device of any one of examples 59 to 70, wherein the one or more insulated electrodes are disposed along a plane substantially parallel to the substantially flat surface.

In a 72nd example, the optical device of any one of examples 59 to 71, wherein a fill level of the second fluid exceeds a height of the raised surface.

In a 73rd example, the optical device of any one of examples 56 to 72, further comprising a transparent substrate adjacent the one or more electrodes that are insulated from the first and second fluids.

In a 74th example, the optical device of any one of examples 56 to 73, wherein the one or more electrodes in electrical communication with the first fluid are configured to transmit visible light therethrough.

In a 75th example, the optical device of any one of examples 56 to 74, wherein the waveguide is configured to couple light into the electro wetting device substantially perpendicular to an optical axis of the electro wetting device.

In a 76th example, an optical device comprising: a chamber having an optical input and an optical output; a first fluid contained in the chamber; a second fluid contained in the chamber, wherein an interface is between the first fluid and the second fluid; one or more electrodes that are insulated from the first and second fluids; and one or more electrodes in electrical communication with the first fluid, wherein the optical device is configured such that a position of the interface is based at least in part on voltages applied between the one or more insulated electrodes and the one or more electrodes in electrical communication with the first fluid; wherein with the interface at first position the optical device is configured to deliver light from the optical input to the optical output; wherein with the interface at a second position the optical device is configured to impede light from propagating from the optical input to the optical output.

In a 77th example, the optical device of example 76, wherein the interface is configured to turn the light by total internal reflection. In a 78th example, the optical device of example 76, wherein the interface is configured to turn the light by refraction.

In a 79th example, the optical device of example 76, further comprising a waveguide coupled to the input to input light into the chamber.

In a 80th example, the optical device of example 76, configured to tilt the interface to transition between the first and second positions.

In a 8lth example, the optical device of example 76, configured to change the curvature of the interface to transition between the first and second positions.

In a 82th example, the optical device of example 76, wherein the chamber comprises a base and a raised portion.

In a 83th example, the optical device of example 76, wherein the interface in the first position can turn the light from the input on a side of the chamber so that the turned light propagates through a base of the chamber to the optical output.

Additional Details

In the disclosure provided above, apparatus, systems, and methods for control of a lens are described in connection with particular example implementations. It will be understood, however, that the principles and advantages of the implementations can be used for any other applicable systems, apparatus, or methods. While some of the disclosed implementations may be described with reference to analog, digital, or mixed circuitry, in different implementations, the principles and advantages discussed herein can be implemented for different parts as analog, digital, or mixed circuitry. In some figures, four electrodes (e.g., insulated electrodes) are shown. The principles and advantages discussed herein can be applied to implementations with more than four electrodes or fewer than four electrodes.

The principles and advantages described herein can be implemented in various apparatuses. Examples of such apparatuses can include, but are not limited to, consumer electronic products, parts of the consumer electronic products, electronic test equipment, etc. The principles and advantages described herein relate to lenses. Examples products with lenses can include a mobile phone (for example, a smart phone), healthcare monitoring devices, vehicular electronics systems such as automotive electronics systems, webcams, a television, a computer monitor, a computer, a hand-held computer, a tablet computer, a laptop computer, a personal digital assistant (PDA), a refrigerator, a DVD player, a CD player, a digital video recorder (DVR), a camcorder, a camera, a digital camera, a copier, a facsimile machine, a scanner, a multi-functional peripheral device, a wrist watch, a clock, etc. Further, apparatuses can include unfinished products.

In some implementations, the methods, techniques, microprocessors, and/or controllers described herein are implemented by one or more special-purpose computing devices. The special-purpose computing devices may be hard-wired to perform the techniques, or may include digital electronic devices such as one or more application- specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs) that are persistently programmed to perform the techniques, or may include one or more general purpose hardware processors programmed to perform the techniques pursuant to program instructions in firmware, memory, other storage, or a combination. The instructions can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of a non- transitory computer-readable storage medium. Such special-purpose computing devices may also combine custom hard-wired logic, ASICs, or FPGAs with custom programming to accomplish the techniques. The special-purpose computing devices may be desktop computer systems, server computer systems, portable computer systems, handheld devices, networking devices or any other device or combination of devices that incorporate hard-wired and/or program logic to implement the techniques.

The processor(s) and/or controller(s) described herein can be coordinated by operating system software, such as iOS, Android, Chrome OS, Windows XP, Windows Vista, Windows 7, Windows 8, Windows Server, Windows CE, Unix, Linux, SunOS, Solaris, iOS, Blackberry OS, VxWorks, or other compatible operating systems. In other implementations, the computing device may be controlled by a proprietary operating system. Conventional operating systems control and schedule computer processes for execution, perform memory management, provide file system, networking, I/O services, and provide a user interface functionality, such as a graphical user interface (“GUI”), among other things.

The processor(s) and/or controller(s) described herein may implement the techniques described herein using customized hard-wired logic, one or more ASICs or FPGAs, firmware and/or program logic which causes microprocessors and/or controllers to be a special-purpose machine. According to one implementation, parts of the techniques disclosed herein are performed by a processor (e.g., a microprocessor) and/or other controller elementss in response to executing one or more sequences instructions contained in a memory. Such instructions may be read into the memory from another storage medium, such as storage device. Execution of the sequences of instructions contained in the memory causes the processor or controller to perform the process steps described herein. In alternative implementations, hard-wired circuitry may be used in place of or in combination with software instructions.

Moreover, the various illustrative logical blocks and modules described in connection with the implementations disclosed herein can be implemented or performed by a machine, such as a processor device, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A processor device can be a microprocessor, but in the alternative, the processor device can be a controller, microcontroller, or state machine, combinations of the same, or the like. A processor device can include electrical circuitry configured to process computer-executable instructions. In another implementation, a processor device includes an FPGA or other programmable device that performs logic operations without processing computer-executable instructions. A processor device can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Although described herein primarily with respect to digital technology, a processor device may also include primarily analog components. For example, some or all of the rendering techniques described herein may be implemented in analog circuitry or mixed analog and digital circuitry.

Unless the context clearly requires otherwise, throughout the description and the claims, the words“comprise,”“comprising,”“include,”“including,” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” The words“coupled” or connected,” as generally used herein, refer to two or more elements that can be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words“herein,” “above,”“below,” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the Detailed Description using the singular or plural number can also include the plural or singular number, respectively. The words“or” in reference to a list of two or more items, is intended to cover all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list. All numerical values provided herein are intended to include similar values (e.g., within a range of measurement error).

Although this disclosure contains certain implementations and examples, it will be understood by those skilled in the art that the scope extends beyond the specifically disclosed implementations to other alternative implementations and/or uses and obvious modifications and equivalents thereof. In addition, while several variations of the implementations have been shown and described in detail, other modifications will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or sub-combinations of the specific features and aspects of the implementations may be made and still fall within the scope of this disclosure. It should be understood that various features and aspects of the disclosed implementations can be combined with, or substituted for, one another in order to form varying modes of the implementations. Any methods disclosed herein need not be performed in the order recited. Thus, it is intended that the scope should not be limited by the particular implementations described above.

Conditional language, such as, among others,“can,”“could,”“might,” or “may,” unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations include, while other implementations do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more implementations or that one or more implementations necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular implementation. Any headings used herein are for the convenience of the reader only and are not meant to limit the scope.

Further, while the devices, systems, and methods described herein may be susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but, to the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the various implementations described. Further, the disclosure herein of any particular feature, aspect, method, property, characteristic, quality, attribute, element, or the like in connection with an implementation or embodiment can be used in all other implementations or embodiments set forth herein. Any methods disclosed herein need not be performed in the order recited. The methods disclosed herein may include certain actions taken by a practitioner; however, the methods can also include any third-party instruction of those actions, either expressly or by implication.

The ranges disclosed herein also encompass any and all overlap, sub ranges, and combinations thereof. Language such as“up to,”“at least,”“greater than,”“less than,”“between,” and the like includes the number recited. Numbers preceded by a term such as“about” or“approximately” include the recited numbers and should be interpreted based on the circumstances (e.g., as accurate as reasonably possible under the circumstances, for example ±1%, ±3%, ±5%, ±10%, ±15%, etc.). For example,“about 3.5 mm” includes“3.5 mm.” Recitation of numbers and/or values herein should be understood to disclose both the values or numbers as well as“about” or“approximately” those values or numbers, even where the terms“about” or“approximately” are not recited. For example, recitation of“3.5 mm” includes“about 3.5 mm.” Phrases preceded by a term such as“substantially” include the recited phrase and should be interpreted based on the circumstances (e.g., as much as reasonably possible under the circumstances). For example,“substantially constant” includes “constant.” Unless stated otherwise, all measurements are at standard conditions including ambient temperature and pressure.