TW202011075A - Electrowetting devices with suspended particles - Google Patents

Abstract

An electrowetting device, such as a liquid lens, can have a first fluid and a second fluid contained in a chamber. A plurality of particles can be suspended in the chamber. The plurality of particles can be suspended at the interface, spanning across the interface, constrained within the first fluid, within the second fluid, or with an additional constraining layer. The plurality of particles can form a monolayer, or can be multiple layers thick. The particles can modify the refractive index of at least one of the fluids. The particles can modify the surface tension of the interface.

Description

Electrowetting device with suspended particles

This application claims the rights and interests of US Provisional Patent Application No. 62/675,036, titled "ELECTROWETTING DEVICES WITH SUSPENDED PARTICLES", filed on May 22, 2018. The entire contents of the above application are hereby incorporated by reference and constitute a part of all the contents disclosed in this specification.

Some embodiments of this disclosure relate to electrowetting devices (eg, liquid lenses) that can have suspended particles in one or more fluids of the electrowetting devices.

Although some types of electrowetting devices and liquid lenses are known, there is still a need for improved electrowetting devices and liquid lenses.

Some exemplary embodiments are summarized below for illustrative purposes. These embodiments are not limited to the specific embodiments described herein. Embodiments may include several novel features, none of which are solely responsible for their desirable attributes or are necessary for embodiments.

Some embodiments disclosed herein may be related to an electrowetting device, which may include a chamber, a first fluid contained in the chamber, and a second liquid contained in the chamber fluid. The interface may be between the first fluid and the second fluid. In some embodiments, the first fluid and the second fluid may be substantially immiscible to form the interface. One or more insulated electrodes may be insulated from the first fluid and the second fluid. One or more electrodes may be in electrical communication with the first fluid. The location of the fluid interface may be based at least in part on the voltage applied between the one or more insulated electrodes and the one or more electrodes in electrical communication with the first fluid. A plurality of particles can be suspended in the chamber.

The particles may have an outer surface with a first area and a second area. The second region may be more hydrophobic than the first region. Each of the plurality of particles may have a hydrophobic coating covering approximately half of the particles. The particles can be positioned at the interface (eg, fluid interface). The first part of the plurality of particles may be in the first fluid, and the second part of the plurality of particles may be in the second fluid. The electrowetting device may have a constrained fluid layer, and the plurality of particles may be constrained in the constrained fluid layer. The constrained fluid layer and the second fluid may be substantially immiscible. The additional fluid layer may separate the constrained fluid layer from the first fluid. The additional fluid layer may be substantially immiscible with the first fluid and/or with the constraining fluid layer. The confinement layer may be an aqueous solution, and the particles may be hydrophilic. The second fluid and/or the additional fluid layer may include oil, and the particles may be oleophobic. The constrained fluid layer and the first fluid may be substantially immiscible. The additional fluid layer may separate the constrained fluid layer from the second fluid. The additional fluid layer may be substantially immiscible with the second fluid and/or with the constraining fluid layer. The constraining layer may be oil, and the particles may be oleophilic. The second fluid and/or the additional fluid layer may include an aqueous solution, and the particles may be hydrophobic. The plurality of particles can be arranged as a single layer. The plurality of particles may be separated from each other. The plurality of particles can be charged so that the plurality of particles repel each other. The plurality of particles can produce a diffraction grating. The plurality of particles can be constrained in the first fluid. The plurality of particles can be constrained in the second fluid. The plurality of particles can form a layer having a thickness of a plurality of particles. The plurality of particles can provide a layer having a refractive index higher than about 1.6. The plurality of particles may provide a layer having a refractive index higher than the refractive index of the adjacent layer by at least about 0.3. The plurality of particles can provide a microlens array. The chamber may include a base and side walls. The one or more insulated electrodes can be positioned on the base. The one or more insulated electrodes may be positioned on the side wall. The electrowetting device may be a liquid lens. The plurality of particles may include fullerene, buckminsterfullerene, quantum dots, nanoparticles, glass beads, and/or zinc oxide.

Some embodiments disclosed herein may be related to a method of making an electrowetting device. The method may include the steps of positioning the first fluid and the second fluid in the cavity. The interface may be between the first fluid and the second fluid. In some embodiments, the first fluid and the second fluid may be substantially immiscible to form the interface (eg, fluid interface). The method may include the step of positioning a plurality of particles in the cavity. The method may include the step of forming one or more insulated electrodes, which may be insulated from the first fluid and the second fluid. The method may include the step of forming one or more electrodes, which may be in electrical communication with the first fluid. The location of the interface may be based at least in part on the voltage applied between the one or more insulated electrodes and the one or more electrodes in electrical communication with the first fluid.

The particles may have an outer surface with a first area and a second area. The second region may be more hydrophobic than the first region. The method may include the step of applying a hydrophobic coating to approximately half of each of the plurality of particles. The method may include the step of positioning the plurality of particles at the fluid interface, wherein the first portion of the plurality of particles is in the first fluid and the second portion of the plurality of particles is in the second fluid. The method may include the step of positioning the constrained fluid layer in the cavity. The step of positioning the plurality of particles may include the step of: constraining the plurality of particles in the constrained fluid layer. The step of positioning the plurality of particles may include the step of forming a single layer of the particles. The method may include the step of applying electric charges to the plurality of particles. The plurality of particles can produce a diffraction grating. The step of positioning the plurality of particles may include the step of: constraining the plurality of particles in the first fluid. The step of positioning the plurality of particles may include the step of: constraining the plurality of particles in the second fluid.

Some embodiments disclosed herein may be related to a method that includes the steps of applying a coating to a plurality of particles. The coating can change the wetting properties of the plurality of particles. The method may include the steps of masking the second portion of the plurality of particles, and removing the paint from the first portion of the plurality of particles.

The step of masking the second part may include the step of floating the plurality of particles in the fluid, for example, wherein the second part is immersed in the fluid and the first part is exposed. The step of removing the coating may include the step of exposing the first portions of the plurality of particles to ultraviolet (UV) light. The coating can cover substantially half of the particles.

Some embodiments disclosed herein may be related to a liquid lens, which may include a first layer and a second layer, the first layer includes a first fluid, and the second layer includes a second fluid. The first layer may have a first refractive index. A plurality of particles can be suspended in the second fluid. The second layer may have a second refractive index that differs from the first refractive index by at least about 0.2, 0.3, 0.4, 0.6, 0.8, or greater, although other values are also possible. The second refractive index may be higher or lower than the first refractive index.

Electrowetting equipment

FIG. 1 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens) 10. The electrowetting device 10 may have a cavity 12 that contains at least two fluids (eg, liquid), such as a first fluid 14 and a second fluid 16. The two fluids may be substantially immiscible, so that the fluid interface 15 is formed between the first fluid 14 and the second fluid 16. Although some embodiments disclosed herein show a fluid interface between two fluids directly in contact with each other, the interface may be formed by a diaphragm or other intermediate structure or material between the two fluids. For example, the embodiments disclosed herein can be modified to use a variety of different fluids, such as those fluids that can be mixed upon direct contact. In some embodiments, the two fluids 14 and 16 may be immiscible enough to form the fluid interface 15. The interface 15 can refract light at the same optical magnification as the lens when it is bent. The first fluid 14 may be electrically conductive, and the second fluid 16 may be electrically insulating. In some embodiments, the first fluid 14 may be a polar fluid, such as an aqueous solution. In some embodiments, the second fluid 16 may be oil. The first fluid 14 may have a higher dielectric constant than the second fluid 16. The first fluid 14 and the second fluid 16 may have different refractive indexes, for example, so that light can be refracted when passing through the fluid interface 15. The first fluid 14 and the second fluid 16 may have substantially similar densities, which may prevent either of the fluids 14 and 16 from floating relative to the other.

The cavity 12 may include a portion having the shape of a frustum or a truncated cone. The cavity 12 may have angled side walls. The cavity 12 may have a narrow portion and a wide portion, where the side walls are closer together, and at the wide portion, the side walls are separated. In the orientation shown, the narrow portion may be at the bottom end of the cavity 12, and the broad portion may be at the top end of the cavity 12, however, various other orientations may be used to position the electrowetting disclosed herein Device 10. The edge of the fluid interface 15 may contact the angled side wall of the cavity 12. The edge of the fluid interface 15 may contact the portion of the cavity 12 having the shape of a frustum or a truncated cone. Various other cavity shapes can be used. For example, the cavity may have curved side walls (eg, curved in the cross-sectional views of FIGS. 1-2). The side wall may conform to the shape of a part of a sphere, ring, or other geometric shape. In some embodiments, the cavity 12 may have a cylindrical shape. In some embodiments, the cavity may have a flat surface, and the fluid interface may contact the flat surface (eg, when a drop of second fluid 16 is on the base of the cavity 12).

The lower window 18, which may include a transparent plate, may be below the cavity 12. The upper window 20, which may include a transparent plate, may be above the cavity 12. The lower window 18 may be positioned at or near the narrow portion of the cavity 12 and/or the upper window 20 may be positioned at or near the wide portion of the cavity 12. The lower window 18 and/or the upper window 20 may be configured to transmit light through the lower window and/or the upper window. The lower window 18 and/or the upper window 20 can transmit sufficient light to form an image, for example, on the imaging sensor of the camera. In some cases, the lower window 18 and/or the upper window 20 may absorb and/or reflect a portion of the light illuminating the lower window and/or the upper window.

One or more first electrodes 22 (eg, insulated electrodes) may be insulated from the fluids 14 and 16 in the cavity 12, for example, by an insulating material 24. One or more second electrodes 26 may be in electrical communication with the first fluid 14. The one or more second electrodes 26 may be in contact with the first fluid 14. In some embodiments, the one or more second electrodes 26 may be capacitively coupled to the first fluid 14. A voltage can be applied between the electrodes 22 and 26 to control the shape of the fluid interface 15 between the fluids 14 and 16, for example to change the focal length of the electrowetting device 10. A direct current (DC) voltage signal may be provided to one or both of the electrodes 22 and 26. An alternating current (AC) voltage signal may be provided to one or both of the electrodes 22 and 26. The electrowetting device 10 may respond to a root mean square (RMS) voltage signal caused by the applied AC voltage. In some embodiments, the AC voltage signal may hinder charge accumulation in the electrowetting device 10, and in some embodiments that utilize DC voltage, charge accumulation in the electrowetting device 10 may occur. In some embodiments, the first fluid 14 and/or one or more second electrodes 26 may be grounded. In some embodiments, one or more first electrodes 22 may be grounded. In some embodiments, a voltage may be applied to the first electrode 22 or the second electrode 26 (but not both) to generate a voltage difference. In some embodiments, a voltage signal may be applied to both the first electrode 22 and the second electrode 26 to generate a voltage difference.

FIG. 1 shows the electrowetting device 10 in a first state where no voltage is applied between the electrodes 22 and 26, and FIG. 2 shows the electrowetting device in a second state where a voltage is applied between the electrodes 22 and 26 10. The chamber 12 may have one or more side walls made of hydrophobic material. For example, the insulating material 24 may be parylene, which may be insulating and hydrophobic, however, various other suitable materials may be used. When no voltage is applied, the hydrophobic material on the sidewall can repel the first fluid 14 (eg, aqueous solution), so that the second fluid 16 (eg, oil) can cover a relatively large area of the sidewall to produce the fluid interface 15 shown in FIG. 1 shape. When a voltage is applied between the first electrode 22 and the first fluid 14 (for example, via the second electrode 26), the first fluid 14 can be attracted to the first electrode 22, which can drive the position of the fluid interface 15 below the sidewall, More parts of the sidewall are brought into contact with the first fluid 14. Based on the principle of electrowetting, changing the applied voltage difference can change the contact angle between the edge of the fluid interface 15 and the surface of the cavity 12 (eg, the angled sidewall of the truncated cone portion of the cavity 12). The fluid interface 15 can be driven to various positions by applying different amounts of voltage between the electrodes 22 and 26, which can produce different focal lengths or different amounts of optical magnification for the electrowetting device 10.

FIG. 3 shows a plan view of an example embodiment of the electrowetting device 10. In some embodiments, the one or more first electrodes 22 (eg, insulated electrodes) may include multiple electrodes 22 positioned at multiple locations on the electrowetting device 10. The electrowetting device 10 can have four electrodes 22a, 22b, 22c, and 22d, which can be positioned in the four quadrants of the electrowetting device 10. In other embodiments, the one or more first electrodes 22 may include various numbers of electrodes (eg, 1 electrode, 2 electrodes, 4 electrodes, 6 electrodes, 8 electrodes, 12 electrodes, 16 Electrodes, 32 electrodes, or more, or any value in between). Although various examples with even number of insulated electrodes 22 are provided herein, odd numbers of insulated electrodes 22 may be used. The electrodes 22a-d can be driven independently (e.g. applying the same or different voltages to the electrodes), which can be used to position the fluid interface 15 at different locations on different parts of the electrowetting device 10 (e.g. quadrant) . FIG. 4 shows a cross-sectional view taken through the opposing electrodes 22a and 22c. If more voltage is applied to the electrode 22c than to the electrode 22a, as shown in FIG. 4, then the fluid interface 15 can be pulled to the quadrant of the electrode 22c compared to the quadrant of the electrode 22a The side walls are further down.

The inclined fluid interface 15 can redirect the light transmitted through the electrowetting device 10. The electrowetting device 10 may have a shaft 28. The axis 28 may be the axis of symmetry of at least a portion of the electrowetting device 10. For example, the cavity 12 may be substantially rotationally symmetrical about the axis 28. The truncated cone portion of cavity 12 may be substantially rotationally symmetrical about axis 28. The axis 28 may be the optical axis of the electrowetting device 10. For example, the curved and non-tilted fluid interface 15 may converge light toward the axis 28 or diverge light away from the axis. In some embodiments, the axis 28 may be the longitudinal axis of the electrowetting device 10. The tilted fluid interface 15 may turn the light 30 passing through the tilted fluid interface to an optical tilt angle 32 relative to the axis 28. The light 30 passing through the inclined fluid interface 15 may converge toward a certain direction or diverge away from this direction, which is inclined by an optical tilt angle 32 relative to the direction in which the light enters the electrowetting device 10. The fluid interface 15 can be tilted up to a solid tilt angle 34 that produces an 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 refractive indices of the fluids 14 and 16.

The optical tilt angle 32 generated by the fluid interface 15 can be used by the camera system to provide optical image stabilization, off-axis focusing, and so on. In some cases, different voltages may be applied to the electrodes 22a-d to compensate for the force applied to the electrowetting device 10 so that the electrowetting device 10 maintains positive axis focus. A voltage can be applied to control the curvature of the fluid interface 15, produce the required optical magnification or focal length and the tilt of the fluid interface 15, and produce the desired optical tilt (such as the direction and amount of optical tilt). Therefore, the electrowetting device 10 can be used in a camera system to produce a variable focal length while producing optical image stabilization. Suspended particles

FIG. 5 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens) 10. The electrowetting device 10 may include a plurality of particles 40 that may be suspended at the fluid interface 15. FIG. 6 shows an example embodiment of particles 40. The particles 40 can form a single layer at the fluid interface 15. In some configurations, the particles 40 can cross the fluid interface 15. The particles 15 can move together with the fluid interface. For example, when a voltage is applied to the electrode, the fluid interface 15 can move, and the particles 40 can move together with the fluid interface 15. The fluid interface 15 may extend substantially across the middle of the particle 40. When the fluid interface moves, the fluid interface 15 may deviate from the middle of the particles 40, especially when the fluid interface 15 is bent. And, in some cases, the manufacturing tolerance may make the particles 40 have a configuration that positions the fluid interface with some deviation from the middle, or the particles 40 may be designed to position the fluid interface 15 on the particles 40 other than the middle, As discussed in this article.

The particles 40 may have a first portion 42 (eg, about half) in the first fluid 14 and a second portion 44 (eg, about half) in the second fluid 16. The first portion 42 may attract the first fluid 14 and/or repel the second fluid 16. The second portion 44 may attract the second fluid 16 and/or repel the first fluid 14. For example, the first fluid may be an aqueous solution (eg, water), and the first portion 42 may be hydrophobic and/or the second portion 44 may be hydrophobic. The second fluid 16 may be oil, and the first portion 42 of the particles 40 may be oleophobic and/or the second portion 44 may be oleophobic. One of the sections 42, 44 may be more hydrophobic, more hydrophilic, more oleophobic, or more lipophilic than the other of the sections 44, 42. One or more coatings can be applied to the particles 40, for example, to produce the properties discussed herein. A first coating may be applied to the first portion 42 and a second coating may be applied to the second portion 44. In some cases, the coating may be applied to only one of the sections 42 or 44. In some cases, parylene coating may be applied to a portion (eg, about half) of the particles 40 to create hydrophobic areas. Various other configurations are possible. For example, the particles 40 can be divided into parts 42 and 44 using other ratios (eg 60:40, 70:30, etc.). In some cases, the particles can be divided into more than two parts. For example, the middle third of the particles 40 may be neutral, or less hydrophobic, less hydrophilic, less oleophobic, or less lipophilic than the portions 42,44.

In some embodiments, a coating (eg, parylene) may be applied to the particles, for example, by spraying or any other suitable deposition technique. The particles can be placed in the fluid so that the particles float with the exposed and immersed parts. The floating particles can be exposed to ultraviolet (UV) light (for example, using a UV lamp or other light source), which can remove the parylene layer from the exposed part of the particles or change its hydrophobicity. The immersed part can retain the parylene coating, otherwise it will remain hydrophobic. The particles may be processed separately from the manufacture of the electrowetting device 10 (eg liquid lens), for example by floating the particles in a separate fluid. Alternatively, for example, before applying the first fluid, the particles may float in the second fluid 16 for treatment (eg UV light application). Other suitable techniques (such as masking, chemical etching, photolithography, etc.) can be used to make the particles 40 having two portions 42, 44 with different wetting properties. Some examples of using parylene are disclosed, however, other suitable coatings can be used to provide applicable wetting properties discussed herein.

Various types of particles 40 can be used in conjunction with the various embodiments disclosed herein. The particles 40 may be glass beads (such as glass microspheres or glass nanospheres), fullerenes (such as buckminsterfullerene (buckminsterfullerene), often referred to as bucky balls), quantum dots, nanoparticles Rice particles, or any other suitable particulate material. Various materials can be used, including but not limited to glass, carbon, zinc oxide, titanium oxide, zinc sulfide, lead sulfide, cadmium telluride, cadmium selenide, lead selenide, zinc cadmium selenide, or any other suitable material. The particles can have any suitable size, such as about 0.7 nm, about 1 nm, about 1.5 nm, about 3 nm, about 5 nm, about 7 nm, about 10 nm, about 15 nm, about 20, about 25 nm, about 30 nm, about 40 nm, about 50 nm, about 70 nm, about 100 nm, about 150 nm, about 200 nm, about 250 nm, about 300 nm, about 400 nm, about 500 nm, about 700 nm, about 1 micron, About 1.5 microns, about 2 microns, about 3 microns, about 5 microns, about 7 microns, about 10 microns, or any value therebetween, or any range bounded by any combination of these values, however, in some cases it may be Use other particle sizes. In the drawings, the particles 40 and other elements are not necessarily drawn to scale, but the sizes and proportions of various components in the drawings do form part of the disclosure.

7 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens) 10. The electrowetting device 10 may have a constrained fluid layer 46, which may hold the particles 40. The fluid of the constraining layer 46 may be substantially immiscible with the fluid adjacent to the constraining layer 46, for example, to form a fluid interface therebetween. By way of example, the second fluid 16 may be oil, and the constraining fluid layer 46 may have an aqueous solution (eg, water). The particles 40 may be hydrophilic and/or oleophobic, such that the particles are constrained in the constraining fluid layer 46. An additional fluid layer 48, which may be oil, may be provided on the opposite side of the constraining layer 46, which may prevent the particles 40 from moving into the first fluid 14. The first fluid 14 may be the same type of fluid as the constraining fluid layer 46, however, different types of fluid may be used. The second fluid 16 may be the same type of fluid as the additional fluid layer 48, however, different types of fluids may also be used. The additional fluid layer 48 (eg, oil or other insulating material) may insulate the fluid (eg, aqueous solution or other conductive liquid) of the constraining layer 46 from the first fluid 14 and/or from the electrode 26. Therefore, no voltage difference is formed between the electrode 22 and the fluid of the confinement layer 46. Therefore, when a voltage is applied to drive the electrowetting device 10, the wetting of the fluid of the constraining layer 46 on the chamber wall is not substantially changed.

FIG. 8 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens) 10. In FIG. 8, the confinement layer 46 may be oil, and the first fluid 14 may be an aqueous solution (eg, water). The particles 40 may be hydrophobic and/or lipophilic, so that the particles are confined in the confinement layer 46. The additional fluid layer 48 may be an aqueous solution and may be disposed between the constraining layer 46 and the second fluid 16, the constraining layer and the second fluid may be oil. The additional fluid layer 48 may prevent particles from moving into the second fluid 16. The second fluid 16 may be the same type of fluid as the constraining fluid layer 46, however, different types of fluids may be used. The first fluid 14 may be the same type of fluid as the additional fluid layer 48, however, different types of fluids may also be used. The confinement layer fluid 46 (eg, oil or other insulating material) may insulate the additional fluid layer 48 (eg, an aqueous solution or other conductive liquid) from the first fluid 14 and/or from the electrode 26. Therefore, no voltage difference is formed between the electrode 22 and the fluid of the additional layer 48. Therefore, when a voltage is applied to drive the electrowetting device 10, the wetting of the fluid of the extra layer 48 on the chamber wall is not substantially changed.

As the first fluid 14 is pulled toward the electrode 22, the additional fluid layer 48, the constraining fluid layer 46, and the second fluid 16 may be deformed (e.g., similar to the discussion of FIGS. 1 and 2). The particles 40 can move together with the constraining layer 46. Different driving voltages can use different curvatures and/or orientations to locate the particle layer and the fluid interface. In some embodiments, the electrowetting device 10 may be configured (eg, the size and shape of the cavity 12, the amount and type of fluid used, the manner of driving the electrodes) such that the constraining layer 46 and/or the fluid interface 15 The area of operation has a substantially constant area across the operating range of the movement (for example, a change of no more than about 1%, about 3%, about 5%, about 7%, about 10%, or about 15%, or any value or range therebetween ). For example, when driving the fluid interface 15 below the side wall of the cone, the curvature of the fluid interface 15 may increase. As the fluid moves in the electrowetting device 10, this may facilitate maintaining a uniform spacing between the particles 40 and/or a uniform thickness of the particles, etc.

The constraining layer 46 may have a thickness that substantially produces a single layer of particles across the constraining layer 46. The thickness of the constraining layer 46 may be about 100%, about 105%, about 110%, about 120%, about 130%, about 140%, about 150%, about 160%, about 170%, about 180 of the diameter of the particles 40 %, about 190%, or about 200%, or any value therebetween, or any range bounded by any combination of these values, however, other thicknesses may be used in some cases. The additional fluid layer 48 may be a thin layer, which may be thinner than the constraining layer 46 in some cases, however it may also be thicker than or the same as the constraining layer 46 in some embodiments. The additional layer may have a thickness that is sufficient to prevent the fluid of the constraining layer 46 from mixing with another fluid in the liquid lens 10 (eg, the first fluid 14 in FIG. 7 or the second fluid 16 in FIG. 8 ).

9 and 10, in some embodiments, the constraining layer 46 may have a thickness that allows the particles 40 to stack. The particles 40 may form a layer having a thickness of a plurality of particles 40. Depending on the size of the particles and the thickness of the layer, the stack of particles 40 may have 2, 5, 10, 20, 30, 50, 70, 100, 150, 200, 250, 300, 400, 500, 700, 1000, 1200, Particle thicknesses of 1500, 1700, 2000, 2500, 3000, 3500, 4000, 5000 or greater, or any value therebetween, or any range bounded by any combination of these values, however, other thicknesses may be used. The constraining layer 46 may have a thickness that is configured to produce a stack of particles 40 having a thickness, as described herein. In some cases, the layer of particles 40 may have a substantially uniform thickness across the constraining layer 46. The constraining layer 46 may have substantially the same curvature on the first side as the curvature on the second side. In some embodiments, the curvature of the first side and the second side of the constraining layer are different.

FIG. 11 is a cross-sectional view of an example embodiment of an electrowetting device 10 (eg, liquid lens). The particles 40 may be suspended in the second fluid 16, which in some embodiments may be oil. The particles 40 may be lipophilic and/or hydrophobic. Coatings or additives may be applied, or in some cases, the base material of the particles 40 may have oleophilic and/or hydrophobic properties. 12 is a cross-sectional view of an example embodiment of an electrowetting device 10 (eg, liquid lens). The particles 40 may be suspended in the first fluid 14, and in some cases, the first fluid may be an aqueous solution. The particles 40 may be hydrophilic and/or oleophobic. Coatings or additives may be applied, or in some cases, the base material of the particles 40 may have hydrophilic and/or oleophobic properties. The particles 40 may be conductive. The particles 40 may be uniformly and/or completely covered to achieve the wetting properties discussed herein.

The particles 40 may substantially fill the fluid layer containing the particles (eg, fluid 14 in FIG. 11, fluid 16 in FIG. 12, fluid layer 46 in FIGS. 7-10 ). In some cases, additional particles 40 cannot be added while the particles are still contained in the fluid. In some cases, the particles may occupy about 70%, about 80%, about 85%, about 90%, about 95%, about 97%, about 98%, or about 99%, or more of the volume of the layer containing the particles Multiple, or any value in between, or any range bounded by any of these values, but other embodiments are possible.

The particles 40 can reinforce the fluid interface 15. In the liquid lens 10, the surface tension of the fluid interface 15 can affect the position and motion of the fluid interface and the optical quality of the image produced using the liquid lens. For example, tilting the fluid interface 15 may cause the fluid interface 15 to pump fluid from one side of the cavity to the other, which may deform the fluid interface and, in some cases, may allow unwanted waves to propagate across the fluid interface. May cause optical aberrations, such as coma. Also, discontinuities at the transition area between the electrodes 22 and other factors may produce shapes in the fluid interface 15 that produce optical aberrations (eg, trilobal). In some cases, curing the fluid interface 15 can reduce optical aberrations. The particles 40 can attract each other, for example by van der Waals force. In some cases, fluids can prevent particles from sticking together. The particles 40 may be wetted by one or more of the fluids in the electrowetting device 10. In some embodiments, particles 40 may touch adjacent particles 40. Compared with electrowetting devices that do not use suspended particles 40, particles 40 can reduce optical aberrations and improve image quality.

The particles 40 can change the refractive index. The particles 40 may have a higher refractive index than the fluid of the electrowetting device 10. Depending on the material used, the particles 40 may have a refractive index of about 1.4, about 1.5, about 1.6, about 1.7, about 1.8, about 1.9, about 2.0, or higher, or any value in between, or use these values Any range of the world. The difference between the refractive index of the particles 40 and the adjacent fluid layer may be at least about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1.0, or greater, or Any value in between, or any range bounded by these values. The difference in refractive index may be greater than the difference in fluid interface across the first fluid 14 and the second fluid 16. A larger difference in refractive index may allow a smaller optical interface curvature and a smaller fluid movement in the liquid lens 10 to obtain the focusing optical power. The reduced range of motion may allow the liquid lens 10 to be made smaller. The reduced range of motion can also reduce optical aberrations and improve image quality. For example, when a smaller curvature is used to generate the focusing optical magnification, less dispersion and chromatic aberration can occur. Also, when the difference in refractive index is large, the desired optical tilt angle 32 can be obtained with a smaller physical tilt angle 34. Therefore, an optical tilt for performing optical image stabilization can be obtained with a smaller physical tilt and with a smaller fluid movement in the liquid lens 10. Smaller fluid movement can, for example, reduce the amount of optical aberration by reducing dynamic wavefront errors (eg, coma aberration), which can be caused by the deformation of the fluid interface when the fluid tilts or otherwise moves. Smaller fluid movement can also reduce power consumption.

By way of example, referring to FIG. 10, when light is transferred from the first fluid 12 (eg, an aqueous solution) into the confined fluid layer 46 (eg, oil) including the particles 40, the light may be refracted, and the focus of the light may be changed. Compared with when no particles are used (for example, as in FIGS. 1 and 2 ), when particles 40 are used (for example, a higher refractive index is caused for the constraining layer 46 ), light can be refracted more with the same curvature. The particles 40 may be small enough (eg, smaller than the wavelength of light) that the light does not scatter when entering the layer of particles 40 or propagating through the layer of particles.

In some embodiments, the particles 40 may form a microlens array. The particles 40 can be large enough (eg, greater than the wavelength of light) to be sufficient so that individual particles 40 can operate as separate lens members of the microlens array. The microlens array can be tilted, curved, or otherwise moved (eg, via electrowetting) to produce an associated optical effect.

13 is a cross-sectional view of an example embodiment of an electrowetting device 10 (eg, liquid lens). In some embodiments, the particles 40 may form a diffraction grating. The space between the particles 40 may provide a hole that diffracts the grating. The size of the particle size 40 may define the spacing between the holes. The particles 40 can be arranged substantially as a single layer across the fluid interface 15. The particles 40 can be configured to absorb light, reflect light, or otherwise block light from passing through the particles 40. The space between adjacent particles 40 may allow light to pass through the spaces, and the spaces may be small enough to implement a diffraction grating. Charges can be applied to the particles 40 so that the particles repel each other. In some embodiments, the spacing between adjacent particles may depend on the charge applied to the particles. For example, the interval can be adjusted by adjusting the charge. A positive charge can be applied (as shown in Figure 14), or a negative charge can be applied to the particles. Figure 14 shows three of the particles 40, where the fluid interface is omitted from the view. A substantially uniform charge can be applied to the particles 40, and once the particles are suspended in the fluid of the electrowetting device 10, this can promote a substantially uniform spacing of the particles 40. The interval between particles 40 may vary by no more than about 15%, about 10%, about 7%, about 5%, about 3%, about 2%, about 1%, or any of these values Any value or range, however other embodiments are possible. The particles 40 can be charged by passing them through a capacitive plate, but any suitable technique can also be used. The particle 40 may have a first portion 42 and a second portion 44 and may be configured similarly to the particle 40 discussed in connection with FIGS. 5-6. Diffraction gratings can be tilted, curved, or otherwise moved (eg, by electrowetting) to produce associated optical effects. FIG. 13 may be similar to FIG. 6 except that the particles 40 are separated to form a diffraction grating.

15 is a cross-sectional view of an example embodiment of an electrowetting device 10, which may be similar to the example of FIG. 7 except that the particles 40 are spaced apart to form a diffraction grating. The particles 40 can be charged so that they repel each other while being constrained in the constraining layer 46. 16 is a cross-sectional view of an example embodiment of an electrowetting device 10, which may be similar to the example of FIG. 8 except that the particles 40 are spaced apart to form a diffraction grating. The particles 40 can be charged so that they repel each other while being constrained in the constraining layer 46.

Various other electrowetting device designs may use suspended particles similar to the various embodiments disclosed herein. FIG. 17 is a cross-sectional view of an example embodiment of the electrowetting device 10. The insulating electrode 22 may be positioned on the base of the electrowetting device 10 instead of the side wall. A hydrophobic material 25 (eg, a layer) may be provided on the base of the cavity 12. In the undriven state, the second fluid 16 (eg, oil) may cover the hydrophobic material 25. When a voltage difference is applied between the electrode 22 and the first fluid 14 (for example, via the electrode 26), the edge of the second fluid 16 can be pulled inwards so that as the voltage difference increases, the first fluid wets more of the base . The electrode 22 may be a transparent electrode, for example, indium tin oxide is used. In some cases, the lower window 18 is between the cavity 12 and the electrode. In some cases, the electrode 22 may be between the cavity 12 and the lower window 18, as shown in FIG. The electrowetting device 10 may be driven from the bottom (eg, through the base of the cavity), or it may be driven from the side (eg, through the side walls).

FIG. 17 generally corresponds to the example embodiment of FIG. 11 in which particles 40 are suspended in the second fluid 16. FIG. 18 generally corresponds to the example embodiment of FIG. 8 in which particles 40 are constrained in the constraining layer 46. Although not shown, electrowetting similar to FIGS. 17 and 18 can be used similarly to FIGS. 5, 7, 9, 10, 11, 13, 14, and 15, or any other embodiments disclosed herein Device 10. In some cases, suspended particles 40 may tend to sink, which may cause the layer with particles 40 to sag. In some embodiments, driving the electrowetting device 10 from the bottom (eg, as shown in FIGS. 17 and 18) can reduce sagging. Extra details

In the disclosure provided above, devices, systems, and methods have been described in conjunction with specific example embodiments. However, it will be appreciated that the principles and advantages of the embodiments may be applied to any other applicable systems, devices, or methods. The principles and advantages discussed herein can be applied to embodiments having more than four electrodes or less than four electrodes.

The principles and advantages described herein can be implemented in various devices. Examples of such devices may include, but are not limited to, consumer electronics, components of consumer electronics, electronic test equipment, and so on. Some of the principles and advantages described herein are related to lenses. Example products with lenses can include mobile phones (eg smartphones), medical care monitoring equipment, vehicle electronic systems (eg automotive electronic systems), webcams, televisions, computer monitors, computers, handheld computers, tablet computers , Laptops, personal digital assistants (PDAs), refrigerators, DVD players, CD players, digital video recorders (DVR), camcorders, camcorders, digital cameras, copiers, fax machines, scanners, multifunction peripherals Devices, watches, clocks, etc. Further, the device may include unfinished products. Electrowetting devices can be used to implement optical switches, shutters, display devices, and various other types of devices and systems.

Unless the context clearly requires otherwise, the word "include" and the like should be interpreted in an inclusive sense (as opposed to mutually exclusive or exhaustive meaning) throughout the specification and claims; that is, it includes "include , But not limited to" the interpretation of meaning. The term "coupled" or "connected" as generally used herein refers to two or more components that can be selectively connected directly or connected by one or more intermediate components. In addition, when used in this application, the words "this article", "above", "below", and similar terms should refer to the entirety of the application and not to any specific part of the application . If the context permits, the words "singular or plural" in the "embodiments" may include plural or singular numbers, respectively. The word "or" referring to a list of two or more items is intended to cover all the following word interpretations: any of the items in the list, all items in the list, and any combination of items in the list. All numerical values provided in this document are intended to include similar values (eg, values within measurement error range).

Although this disclosure includes certain embodiments and examples, those skilled in the art will understand that the scope extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses, as well as obvious variations and Equivalent. In addition, although several variations of the embodiments have been shown and described in detail, those skilled in the art will readily understand other variations based on this disclosure. It is also expected that various combinations or sub-combinations of specific features and aspects of the embodiments may be made, and such combinations or sub-combinations still fall within the scope of this disclosure. It should be understood that various features and aspects of the disclosed embodiments may be combined or substituted with each other to form a variation mode of the embodiments. Any methods disclosed herein do not need to be performed in the order described. Therefore, the scope is not intended to be limited by the specific embodiments described above.

Unless specifically stated otherwise, or based on the context in which they are used, conditional language (such as "may" or "may") is generally intended to convey that certain embodiments include certain features, components, and/or steps, Other embodiments do not include these features, components, and/or steps. Therefore, such conditional language is generally not intended to imply that one or more embodiments require features, components, and/or steps anyway, or that one or more embodiments must include In the case of input or prompts, it is determined whether these features, components, and/or steps are to be included or executed in any particular embodiment of the logic. Any headings used in this article are for the convenience of the reader and are not meant to limit the scope.

Further, although the devices, systems, and methods described herein can have various variations and alternative forms, the specifics of these devices, systems, and methods have been shown in the drawings and described in detail herein Example. However, it should be understood that the present invention is not limited to the specific forms or methods disclosed, but on the contrary, the present invention is to cover all variants, equivalents, which fall within the spirit and scope of the various embodiments And alternatives. Further, any specific features, aspects, methods, properties, characteristics, qualities, attributes, components, etc. disclosures and embodiments or examples herein can be used in all other embodiments or examples set forth herein in. Any methods disclosed herein do not need to be performed in the order described. The methods disclosed in this article may include certain actions taken by the implementer; however, these methods may also include any third-party instructions for their actions explicitly or implicitly.

The scope disclosed herein also includes any and all overlapping portions, sub-ranges, and combinations thereof. Languages such as "Gundam", "At least", "Greater Than", "Less Than", "Between", etc. include the recorded quantities. Numbers preceded by terms such as "about" or "approximately" include the recorded numbers, and should be interpreted as appropriate (eg, as reasonably accurate as possible in such cases, such as ±1%, ±3%, ±5 %, ±10%, ±15%, etc.). For example, "about 3.5 mm" includes "3.5 mm". Even if the terms "about" or "approximately" are not recorded, the description of the numbers and/or values in this article should be understood as revealing these values or numbers and the values or numbers of "about" or "approximately". For example, the description of "3.5 mm" includes "about 3.5 mm". Sentences preceded by terms such as "substantial" include the stated sentences and should be interpreted as appropriate (for example, interpreted as reasonably as possible in such circumstances). For example, "substantially constant" includes "constant." Unless otherwise stated, all measurements are under standard conditions, including ambient temperature and pressure.

10: Electrowetting equipment 12: cavity 14: First fluid 15: Fluid interface 16: second fluid 18: Lower window 20: Upper window 22: First electrode 24: Insulation material 25: hydrophobic material 26: Second electrode 28: axis 30: light 32: Optical tilt angle 34: entity tilt angle 40: Particle 42: Part One 44: Part Two 46: Constrained fluid layer 48: additional fluid layer 22a: electrode 22b: electrode 22c: electrode 22d: electrode

Certain embodiments will be discussed in detail with reference to the following drawings, where like reference numbers always refer to like features. These drawings are provided for illustrative purposes, and the embodiments are not limited to the specific implementations depicted in the drawings.

Figure 1 is a cross-sectional view of an example embodiment of an electrowetting device.

FIG. 2 shows the electrowetting device in the second state where the voltage is applied.

Figure 3 shows a plan view of an example embodiment of an electrowetting device.

Figure 4 shows a cross-sectional view taken through the opposite electrode.

5 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

FIG. 6 shows an example embodiment of particles.

7 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

8 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

9 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

10 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

11 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

12 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

13 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

FIG. 14 shows an example embodiment of particles.

15 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

16 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

17 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

18 is a cross-sectional view of an example embodiment of an electrowetting device (eg, liquid lens).

Domestic storage information (please note in order of storage institution, date, number) no

Overseas hosting information (please note in order of hosting country, institution, date, number) no

10: Electrowetting equipment

12: cavity

14: First fluid

15: Fluid interface

16: second fluid

18: Lower window

20: Upper window

22: First electrode

24: Insulation material

26: Second electrode

40: Particle

Claims (30)

An electrowetting device, including: One chamber A first fluid, contained in the chamber; A second fluid is contained in the chamber, with an interface between the first fluid and the second fluid; One or more insulated electrodes, insulated from the first fluid and the second fluid; and One or more electrodes in electrical communication with the first fluid, wherein a location of the interface is based at least in part on the one or more insulating electrodes and the one or more electrodes in electrical communication with the first fluid The voltage applied between them; and A plurality of particles are suspended in the chamber. The electrowetting device of claim 1, wherein the particles have an outer surface, the outer surface has a first area and a second area, and wherein the second area is more hydrophobic than the first area . The electrowetting device of claim 1, wherein the particles are positioned at the interface, wherein a first portion of the plurality of particles is in the first fluid and a second portion of the plurality of particles is in the In the second fluid. The electrowetting device of claim 1, further comprising a constrained fluid layer, wherein the plurality of particles are constrained in the constrained fluid layer. The electrowetting device according to any one of claims 1 to 4, wherein the plurality of particles are arranged as a single layer. The electrowetting device according to any one of claims 1 to 4, wherein the plurality of particles are separated from each other. The electrowetting device of claim 6, wherein the plurality of particles are charged so that the plurality of particles repel each other. The electrowetting device according to any one of claims 1 to 4, wherein the plurality of particles generates a diffraction grating. The electrowetting device of claim 1, wherein the plurality of particles are confined in the first fluid. The electrowetting device of claim 1, wherein the plurality of particles are confined in the second fluid. 4. The electrowetting device according to any one of 9 to 10, wherein the plurality of particles form a layer having a thickness of a plurality of particles. The electrowetting device of any one of claims 1 to 4 and 9 to 10, wherein the plurality of particles provide a layer having a refractive index higher than about 1.6. The electrowetting device according to any one of claims 1 to 4 and 9 to 10, wherein the plurality of particles provide a microlens array. The electrowetting device according to any one of claims 1 to 4 and 9 to 10, wherein the electrowetting device is a liquid lens. The electrowetting device according to any one of claims 1 to 4 and 9 to 10, wherein the plurality of particles include fullerene, buckminsterfullerene, quantum dots, nanoparticles , Glass beads, or one or more of zinc oxide. A method for manufacturing an electrowetting device, the method includes the following steps: Positioning a first fluid and a second fluid in a cavity, with an interface between the first fluid and the second fluid; Position a plurality of particles in the cavity; Forming one or more insulated electrodes that are insulated from the first fluid and the second fluid; and One or more electrodes are formed, the one or more electrodes being in electrical communication with the first fluid, wherein a position of the fluid interface is based at least in part on the one or more insulating electrodes and the first fluid The voltage applied between the connected one or more electrodes. The method of claim 16, further comprising the step of applying a hydrophobic coating to approximately half of each of the plurality of particles. The method of claim 16, further comprising the steps of: positioning the plurality of particles at the fluid interface, wherein a first portion of the plurality of particles is in the first fluid and a second portion of the plurality of particles Partly in this second fluid. The method of claim 16, further comprising the step of: positioning a constrained fluid layer in the cavity, and wherein the step of positioning the plurality of particles includes the step of: constraining the plurality of particles in the constrained fluid In the layer. The method according to any one of claims 16 to 19, wherein the step of locating the plurality of particles includes the step of forming a single layer of the particles. The method according to any one of claims 16 to 19, further comprising the step of applying a charge to the plurality of particles. The method of claim 16, wherein the step of locating the plurality of particles includes the step of: constraining the plurality of particles in the first fluid. The method of claim 16, wherein the step of locating the plurality of particles includes the step of: constraining the plurality of particles in the second fluid. A method, including the following steps: Applying a paint to a plurality of particles, wherein the paint changes a wetting property of the plurality of particles; Mask a second part of the plurality of particles; and The paint is removed from a first part of the plurality of particles. The method of claim 24, wherein the step of masking the second portion includes the step of floating the plurality of particles in a fluid, wherein the second portion is immersed in the fluid and the first portion is exposed. The method of any one of claims 24 to 25, wherein the step of removing the coating includes the step of exposing the first portions of the plurality of particles to ultraviolet (UV) light. A liquid lens, including: A first layer, including a first fluid, wherein the first layer has a first refractive index; and A second layer including a second fluid and a plurality of particles suspended in the second fluid, wherein the second layer has a second refractive index, and the difference between the second refractive index and the first refractive index is at least at least About 0.2. The liquid lens of claim 27, wherein the second refractive index differs from the first refractive index by at least about 0.4. The liquid lens of claim 27, wherein the second refractive index differs from the first refractive index by at least about 0.8. The liquid lens according to any one of claims 27 to 29, wherein the second refractive index is higher than the first refractive index.

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