Low-voltage controlled electroosmosis driver and tactile feedback array

Abstract

The invention discloses a low-voltage controlled electroosmosis driver and a tactile feedback array, and relates to the technical field of microfluid electroosmosis driving, the low-voltage controlled electroosmosis driver comprises a liquid storage layer, an electroosmosis pump layer and an output layer; the liquid storage layer is used for storing an electroosmotic fluid working medium; the electroosmotic pump layer is located on the liquid storage layer and comprises an upper electrode, a lower electrode and a porous membrane clamped between the two electrodes, and micron through hole arrays are formed in the upper electrode and the lower electrode; the output layer is an elastic film and is positioned on the electroosmotic pump layer; the liquid storage layer, the electroosmotic pump layer and the output layer are bonded together from bottom to top through an adhesive; the tactile feedback array is formed by arranging a plurality of low-voltage controlled electroosmosis drivers through a plane matrix and is used for providing spatialized tactile feedback information. According to the invention, tactile feedback sufficient to be perceived by skin can be provided within a human body safety voltage range, so that people can obtain real and fine tactile experience in a human-computer interaction process.

Description

Technical Field

[0001] The present invention relates to the technical field of electroosmotic drive in microfluidics, and in particular to an electroosmotic driver and a tactile feedback array controlled by low voltage. Background Art

[0002] Tactile feedback technology reproduces tactile sensations for users by generating feedback information such as touch and vibration on the surface of the human skin, and has been widely applied in the field of human-computer interaction such as virtual reality, remote control, and braille reading. Existing tactile feedback technologies generally form a feedback array with multiple flexible drivers, and realize spatial tactile information feedback by directly stimulating various tactile receptors on the human skin. In order to meet the flexibility and portability of wearables and at the same time achieve the integration of the feedback array, materials such as electrets, dielectric elastomers, and dielectric fluids that are prone to deformation under voltage control are usually used to construct flexible tactile feedback drivers. However, these drivers often require a control voltage of thousands of volts to generate a tactile feedback sufficient for the human skin to perceive, and do not have wearable safety.

[0003] The microfluidic electroosmotic drive technology uses the directional migration of counterions in the electric double layer to drive the fluid flow in the microchannel under an electric field, thereby generating an external output pressure, and has advantages such as large output pressure, fast response, and strong adjustability. In recent years, the microfluidic electroosmotic drive technology has been gradually applied to the fields of tactile display, virtual reality, etc., but its control voltage still needs several hundred volts, which is much higher than the human body safety voltage threshold.

[0004] Therefore, it is an urgent problem for those skilled in the art to propose an electroosmotic driver and a tactile feedback array controlled by low voltage to solve the difficulties existing in the prior art. Summary of the Invention

[0005] In view of this, the present invention provides an electroosmotic driver and a tactile feedback array controlled by low voltage, which can provide tactile feedback sufficient for the skin to perceive within the human body safety voltage range, enabling people to obtain a real and delicate tactile experience during the human-computer interaction process.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An electroosmotic driver and a tactile feedback array controlled by low voltage, the electroosmotic driver controlled by low voltage includes: a liquid storage layer, an electroosmotic pump layer, and an output layer;

[0008] The liquid storage layer is used for storing an electroosmotic fluid working medium;

[0009] The electroosmotic pump layer is located on the liquid storage layer and includes: an upper electrode, a lower electrode, and a porous membrane sandwiched between the two electrodes. The upper electrode and the lower electrode are provided with a micro-hole through-array;

[0010] The output layer is an elastic film located on the electroosmotic pump layer;

[0011] The liquid storage layer, the electroosmotic pump layer and the output layer are bonded together from bottom to top by an adhesive;

[0012] The tactile feedback array is composed of multiple electroosmotic actuators controlled by low voltage arranged in a planar matrix, and is used to provide spatially distributed tactile feedback information.

[0013] Preferably, the liquid storage layer is made of any one of PET, PVC, PI, silica gel or PDMS.

[0014] Preferably, the electroosmotic fluid working medium is propylene carbonate.

[0015] Preferably, the membrane material of the porous membrane is any one of glass fiber, AAO or polycarbonate, and contains micro-nano channels for providing fluid channels for wall charges;

[0016] The porous membrane enhances the electroosmotic output pressure through wall charge enhancement and microchannel space compression, and reduces the electroosmotic control voltage at the same output pressure.

[0017] Preferably, the wall charge enhancement includes: chemically grafting charged groups, self-assembled monolayers, hydrogen peroxide surface modification and plasma treatment;

[0018] The wall charge enhancement is used to increase the wall charge density, thereby increasing the net ion charge density in the channel, enhancing the electroosmotic output, and reducing the electroosmotic control voltage.

[0019] Preferably, the microchannel space compression includes: selecting a membrane material with a small pore diameter, physically compressing the membrane pores;

[0020] The microchannel space compression is used to increase the net ion charge density in the membrane under the same wall charge, enhance the electroosmotic output, and reduce the electroosmotic control voltage.

[0021] Preferably, the materials of the upper electrode and the lower electrode are any one of copper, titanium, silver, gold, platinum or carbon;

[0022] The upper electrode and the lower electrode are bonded to the insulating substrate, and are used to apply a voltage and generate an electric field in the porous membrane to drive the electroosmotic flow of the fluid working medium in the micro-nano channels in the porous membrane.

[0023] Preferably, the output layer is any one of silica gel, PDMS, Ecoflex, SBS or SEBS, and generates a convex deformation under the action of the electroosmotic fluid.

[0024] As can be seen from the above technical solutions, compared with the prior art, the present invention provides an electroosmotic actuator and a tactile feedback array controlled by low voltage, having the following beneficial effects: 1) The present invention significantly improves the wall charge density of the microchannel by the methods of wall charge enhancement and pore size reduction, effectively reducing the control voltage of the electroosmotic actuator and realizing force feedback exceeding the tactile perception threshold of the human skin within the human safe voltage range; 2) The tactile feedback actuator provided by the present invention has good flexibility and portability, and can adapt to the soft skin surface for efficient tactile signal transmission; 3) The structure of the present invention is simple and easy to manufacture. Both the porous membrane and the electrode material can be processed by common cutting techniques, realizing the highly integrated actuator and the high-resolution (millimeter-level) tactile feedback array; 4) The manufacturing cost of the present invention is low, the optional raw materials have a wide source and low price, and there is the potential for application in mass industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0026] Figure 1 Schematic diagram of the structure of the electroosmotic actuator controlled by low voltage of the electroosmotic actuator and the tactile feedback array provided by the present invention;

[0027] Figure 2 Schematic diagram of the structure of the tactile feedback array of the electroosmotic actuator and the tactile feedback array provided by the present invention;

[0028] Figure 3 Schematic diagram of the principle of microfluidic electroosmotic drive provided by the present invention;

[0029] Figure 4 Output photo of the tactile feedback array provided by the present invention under a control voltage of 36V;

[0030] Figure 5 Relationship between the output pressure and the control voltage of the electroosmotic actuator controlled by low voltage provided by the present invention after the space compression and wall charge enhancement of the glass fiber membrane. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the protection scope of the present invention.

[0032] In the present application, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. The terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0033] The present invention discloses an electroosmotic actuator and a tactile feedback array controlled by low voltage. Referring to Figure 1 as shown, the electroosmotic actuator controlled by low voltage includes: a liquid storage layer, an electroosmotic pump layer and an output layer;

[0034] The liquid storage layer is used to store the electroosmotic fluid working medium;

[0035] The electroosmotic pump layer is located on the liquid storage layer and includes: an upper electrode, a lower electrode and a porous membrane sandwiched between the two electrodes. The upper electrode and the lower electrode are provided with a micron through-hole array;

[0036] The output layer is an elastic film and is located on the electroosmotic pump layer;

[0037] The liquid storage layer, the electroosmotic pump layer and the output layer are adhesively bonded together from bottom to top;

[0038] Furthermore, the tactile feedback array is composed of a plurality of electroosmotic actuators controlled by low voltage arranged in a planar matrix, and is used to provide spatialized tactile feedback information.

[0039] Furthermore, the liquid storage layer is made of any one of PET, PVC, PI, silica gel or PDMS.

[0040] Furthermore, the electroosmotic fluid working medium is propylene carbonate.

[0041] Furthermore, the membrane material of the porous membrane is any one of glass fiber, AAO or polycarbonate, and contains micro-nano channels for providing fluid channels for wall charges;

[0042] The porous membrane enhances the wall charge and compresses the microchannel space, improving the electroosmotic output pressure and reducing the electroosmotic control voltage at the same output pressure.

[0043] Furthermore, the wall charge enhancement includes: chemically grafting charged groups, self-assembled monolayers, surface modification with hydrogen peroxide, and plasma treatment;

[0044] The wall charge enhancement is used to increase the wall charge density, thereby increasing the net ion charge density in the channel, enhancing the electroosmotic output, and reducing the electroosmotic control voltage.

[0045] Furthermore, the microchannel space compression includes: selecting a membrane material with a small pore diameter and physically compressing the membrane pores;

[0046] The microchannel space compression is used to increase the net ion charge density in the membrane under the same wall charge, enhance the electroosmotic output, and reduce the electroosmotic control voltage.

[0047] Further, the upper and lower electrode materials are any one of copper, titanium, silver, gold, platinum, or carbon;

[0048] The upper and lower electrodes are bonded to an insulating substrate, used to apply a voltage and generate an electric field in the porous membrane to drive the electroosmotic flow of the fluid working medium in the micro-nano channels in the porous membrane.

[0049] Further, the output layer is any one of silica gel, PDMS, Ecoflex, SBS, or SEBS, and generates a convex deformation under the action of electroosmotic fluid.

[0050] In a specific embodiment, an electroosmotic driver with low voltage control includes a liquid storage layer, an electroosmotic pump layer, and an output layer; the liquid storage layer is made of silica gel material and is used to store propylene carbonate liquid; the electroosmotic pump layer is composed of a glass fiber membrane and upper and lower copper electrodes, where the copper electrodes are attached to the silica gel thin film and are provided with a micron through-hole array; the output layer is an elastic thin film made of Ecoflex-20; the above liquid storage layer, electroosmotic pump layer, and output layer are laminated and bonded together through a silica gel adhesive layer to form an electroosmotic driver.

[0051] The glass fiber membrane realizes wall charge enhancement through hydrogen peroxide treatment and internal microchannel space compression through membrane thickness compression.

[0052] Refer to Figure 2 As shown, it is composed of arranging multiple electroosmotic drivers in a matrix on the same plane and sharing the same liquid storage pool, where the upper and lower electrodes and the glass fiber membrane of a single driver are all circular with a diameter of 3 mm, and the center distance between adjacent drivers is 3 mm.

[0053] Refer to Figure 3As shown, the glass fiber membrane contains microchannels with negatively charged walls. When a voltage is applied between the upper and lower electrodes, the cations in the double electric layer migrate upward under the action of the electric field, driving the fluid flow in the microchannels, causing propylene carbonate to flow from the liquid storage layer to the output layer, thereby causing the film in the output layer to bulge and generating a force feedback externally.

[0054] Referring to Figure 4 As shown, it is the deformation and bulging condition of the output layer of the tactile feedback array after applying a 36V control voltage. The pattern of the controlled bulging array can provide pixelated tactile feedback for the human skin.

[0055] Referring to Figure 5 As shown, a dynamometer was used to measure the pressure of the bulging liquid bubbles in the output layer of the electroosmotic actuator. After the glass fiber membrane was compressed in space and the wall charge was enhanced, the output pressure increased significantly under the same control voltage; the electroosmotic actuator can output a pressure feedback exceeding the human tactile perception threshold under a 20V control voltage, meeting the requirements of safe wearable tactile feedback.

[0056] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The systems and system embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0057] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A low-voltage controlled electroosmotic actuator and a tactile feedback array, characterized in that The low-voltage controlled electroosmotic actuator includes: a liquid storage layer, an electroosmotic pump layer, and an output layer; The liquid storage layer is used to store the electroosmotic fluid working medium; The electroosmotic pump layer is located on the liquid storage layer and includes: an upper electrode, a lower electrode, and a porous membrane sandwiched between the two electrodes. The upper electrode and the lower electrode are provided with a micron through-hole array; The output layer is an elastic thin film located on the electroosmotic pump layer; The liquid storage layer, the electroosmotic pump layer, and the output layer are bonded together from bottom to top by an adhesive; The tactile feedback array is composed of a plurality of low-voltage controlled electroosmotic actuators arranged in a planar matrix, and is used to provide spatially distributed tactile feedback information.

2. The low-voltage controlled electroosmotic actuator and the tactile feedback array according to claim 1, characterized in that The liquid storage layer is made of any one of PET, PVC, PI, silica gel, or PDMS.

3. The low-voltage controlled electroosmotic actuator and the tactile feedback array according to claim 1, characterized in that The electroosmotic fluid working medium is propylene carbonate.

4. The low-voltage controlled electroosmotic actuator and the tactile feedback array according to claim 1, characterized in that The membrane material of the porous membrane is any one of glass fiber, AAO, or polycarbonate, and contains micro-nano channels for providing fluid channels for wall charges; The porous membrane enhances the electroosmotic output pressure through wall charge enhancement and microchannel space compression, and reduces the electroosmotic control voltage under the same output pressure.

5. The low-voltage controlled electroosmotic actuator and the tactile feedback array according to claim 4, characterized in that Wall charge enhancement includes: chemically grafting charged groups, self-assembled monolayers, hydrogen peroxide surface modification, and plasma treatment; Wall charge enhancement is used to increase the wall charge density, thereby increasing the net ion charge density in the channel, enhancing the electroosmotic output, and reducing the electroosmotic control voltage.

6. The low-voltage controlled electroosmotic actuator and the tactile feedback array according to claim 4, characterized in that Microchannel space compression includes: selecting a membrane material with a small pore diameter and physically compressing the membrane pores; Microchannel space compression is used to increase the net ion charge density in the membrane under the same wall charge, enhance the electroosmotic output, and reduce the electroosmotic control voltage.

7. The low-voltage controlled electroosmotic actuator and the tactile feedback array according to claim 4, characterized in that The materials of the upper electrode and the lower electrode are any one of copper, titanium, silver, gold, platinum, or carbon; The upper electrode and the lower electrode are bonded to an insulating substrate for applying a voltage and generating an electric field in the porous membrane to drive the electroosmotic flow of the fluid working medium in the micro-nano channels in the porous membrane.

8. The low-voltage controlled electroosmotic actuator and the tactile feedback array according to claim 1, characterized in that The output layer is any one of silica gel, PDMS, Ecoflex, SBS, or SEBS, and generates a convex deformation under the action of the electroosmotic fluid.

Images