Bendable plane type soft pump driven by dielectric elastomer

Abstract

The invention discloses a bendable plane type soft pump driven by a dielectric elastomer. The pump body comprises a pumping sealing layer, a dielectric elastomer film, a negative pressure sealing layer, a one-way valve and a part of hose; the pumping sealing layer is provided with a fluid inlet and a fluid outlet, the one-way valve is connected with the fluid inlet and the fluid outlet through the hose, fluid flows to the fluid inlet through the one-way valve, flows to the fluid outlet through flow channels among a plurality of unit pumping cavities in the pumping sealing layer and flows out of the one-way valve, and the pumping sealing layer is bonded with the dielectric elastomer film through a bonding surface; the dielectric elastomer film is bonded with the negative pressure sealing layer through a bonding surface, one end of the negative pressure sealing layer is provided with an air exhaust hole, and the air exhaust hole is communicated with a plurality of unit negative pressure cavities on the negative pressure sealing layer through flow channels. The soft pump utilizes voltage to control compression of the dielectric elastomer film and realizes volume change of the pumping cavity under the action of negative pressure so as to pump fluid, the pumping function is kept when the soft pump is bent by utilizing the structural infinitesimal, and the soft pump is suitable for a driving device in a soft robot or wearable equipment.

Description

Technical Field

[0001] This invention relates to a driving device in the field of soft robots and wearables, and more specifically to a bendable planar soft pump driven by a dielectric elastomer. Background Technology

[0002] Pumps, as key power components in fluid dynamics, play a crucial role in natural life systems and soft systems such as soft robots and wearable devices. In biological pumps, mosquitoes use a "dual-pump system" to inhale; squid pump seawater to swim; and in the human body, the heart and muscle pumps maintain the blood circulation system. Mechanical pumps or compressors, as drive components, are widely used in soft robots and wearable devices. However, unlike biological pumps which perfectly adapt to biological systems, their rigid structure and large mass limit the adaptability and autonomy of soft systems. Therefore, developing structural soft pumps adapted to soft systems such as soft robots is essential.

[0003] Currently, a series of innovative soft pumps have been developed and embedded into soft systems such as soft robots and wearable devices, significantly reducing the need for external rigid drive components and improving the system's versatility and autonomy. However, existing soft pumps based on electrohydrodynamics can pump under large-angle bending or deformation, but the pumped medium is part of the pump body itself, making the pump dependent on a specific dielectric fluid. Diaphragm pumps or peristaltic pumps based on dielectric elastomers, electrostatic zippers, and other principles have poor structural flexibility, or their pump chamber volume changes under large-angle bending or deformation, affecting pumping performance. This limits the widespread application of soft pumps in fluid-driven soft robots and wearable devices. Developing pumps capable of pumping different media under large-angle bending or deformation has become one of the key challenges in soft pump research. Summary of the Invention

[0004] To overcome the shortcomings of existing soft pumps, this invention provides a bendable planar soft pump driven by a dielectric elastomer. This pump is entirely made of soft material and utilizes the electrochromic properties of the dielectric elastomer and negative pressure to change the volume of the pumping chamber to pump fluid. The pumping fluid pressure and flow rate can be quantitatively controlled by adjusting the driving voltage characteristics. Furthermore, the soft pump has advantages such as independence from the pumping medium, simple structure, quiet operation, and wide applicability.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention includes a pumping sealing layer, a dielectric elastomer membrane, a negative pressure sealing layer, a one-way valve, and a portion of flexible tubing. One end of the pumping sealing layer has a fluid inlet, and the one-way valve is connected to the fluid inlet via a flexible tubing, which is bonded to the fluid inlet. The other end has a fluid outlet, and the one-way valve is connected to the fluid outlet via a flexible tubing, which is bonded to the fluid outlet. Fluid flows from the one-way valve to the fluid inlet, through flow channels between several pumping chambers on the pumping sealing layer, and then to the fluid outlet, exiting through the one-way valve. The pumping sealing layer and the dielectric elastomer membrane are bonded together via various adhesive surfaces. The dielectric elastomer includes a VHB film, carbon grease, and copper foil. The carbon grease is applied to both sides of the VHB film as a flexible electrode, and the copper foil is adhered to the VHB film. The carbon grease on both sides contacts the upper and lower copper foils, respectively. The dielectric elastomer membrane and the negative pressure sealing layer are bonded together via various adhesive surfaces. One end of the negative pressure sealing layer has an evacuation port, which is connected to several negative pressure chambers on the negative pressure sealing layer via flow channels. The flexible tubing is bonded to the evacuation port.

[0006] The pumping sealing layer and the negative pressure sealing layer are formed by silicone casting and curing or by 3D printing of soft materials, and can support the pre-tension stress of the dielectric elastomer film.

[0007] The VHB film is obtained by stretching VHB tape of a certain thickness in a certain proportion in both directions, with a certain pre-stress and deformation under external force, and the surface of the VHB film has a certain degree of stickiness.

[0008] The carbon grease is a flexible electrode material, which is symmetrically applied to both sides of the membrane using a mask. The uncoated carbon grease is the bonding contact surface.

[0009] The copper foil is bonded to the VHB film and connected to the ink electrodes on both sides, and is connected to an external power source.

[0010] The unit pumping chamber on the pumping sealing layer, the carbon grease on the dielectric elastomer membrane, and the unit negative pressure chamber on the negative pressure sealing layer are arranged in parallel.

[0011] The dielectric elastomer film, hose, pump sealing layer, and negative pressure sealing layer are bonded together using silicone adhesive.

[0012] The bendable and pumpable features of this invention refer to the following two aspects: 1. The soft pump is composed entirely of soft materials and has a relatively thin overall thickness, allowing it to be bent at large angles; 2. Since both the pumping chamber and the negative pressure chamber are composed of multiple independent micro-unit chambers, most of the micro-unit chambers are not affected by bending at large angles, thus enabling the pumping function to still be achieved even when bending at large angles.

[0013] The dielectric elastomer-driven, large-angle bending, pumpable soft pump provided by this invention has the following advantages compared to the prior art: The dielectric elastomer-driven soft pump of the present invention achieves pump cavity volume change to pump fluid by means of the electrochromic properties of the dielectric elastomer and the action of negative pressure. The pumped fluid pressure and flow rate can be quantitatively controlled by adjusting the characteristics of the driving voltage. At the same time, the soft pump has the advantages of being able to pump at large angles, being independent of the pumped medium, having a simple structure, being quiet, and having a wide range of applications.

[0014] The soft pump of this invention utilizes voltage to actively control the pumping output performance, featuring rapid response, a wide controllable range, and a micro-element structure design that allows the soft pump to maintain its pumping performance even when bent at large angles. It is suitable for drive devices in soft robots or wearable devices. Attached Figure Description

[0015] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration: Figure 1 This is a plan view of the present invention and a structural schematic diagram of the pumping sealing layer, the dielectric elastomer membrane, and the negative pressure sealing layer; In the diagram: 1. Pumping sealing layer; 2. Dielectric elastomer membrane; 3. Negative pressure sealing layer; 4. One-way valve; 5. Hoses; 6. Fluid inlet; 7. Fluid outlet; 8. Unit pumping chamber; 9. Flow channel; 10. Adhesive surface; 11. VHB film; 12. Carbon grease; 13. Copper foil; 14. Adhesive surface; 15. Air extraction hole; 16. Unit negative pressure chamber; 17. Flow channel; 18. Adhesive surface. Detailed Implementation

[0016] The invention will now be further described with reference to the accompanying drawings.

[0017] like Figure 1 As shown, the system includes a pumping sealing layer 1, a dielectric elastomer membrane 2, a negative pressure sealing layer 3, a one-way valve 4, and a portion of a hose 5. The pumping sealing layer 1, the dielectric elastomer membrane 2, and the negative pressure sealing layer 3 are bonded together through bonding surfaces 10, 14, and 18. The hose 5 is bonded to the fluid inlet 6, the fluid outlet 7 on the pumping sealing layer 1, and the air extraction hole 15 of the negative pressure sealing layer. The one-way valve 4 is connected to the hose 5 bonded to the pumping sealing layer 1. The adhesive is Kraft silicone sealant from Guangdong Hengda New Material Technology Co., Ltd.

[0018] like Figure 1As shown, the pumping sealing layer 1 has a fluid inlet 6, a fluid outlet 7, and several unit pumping chambers 8, which are connected through a flow channel 9; the dielectric elastomer membrane 2 includes a VHB film 11, carbon grease 12, and copper foil 13. The VHB film 11 is compressible and can undergo elastic deformation under external forces such as negative pressure. The carbon grease 12 is symmetrically applied to both sides of the VHB film 11 through a mask. The unapplied carbon grease is the bonding surface 14. The copper foil 13 is bonded to the VHB film 11 and is connected to the carbon grease 12 on both sides; the negative pressure sealing layer 3 includes an air extraction hole 15 and several unit negative pressure chambers 16, which are connected through a flow channel 17; the unit pumping chambers 8, carbon grease 12, and unit negative pressure chambers 16 are placed in parallel.

[0019] When the unit negative pressure chamber 16 is under negative pressure, due to the pressure difference, the dielectric elastomer membrane 2 is biased to one side of the unit negative pressure chamber 16 to form a dome structure. The copper foil 13 is connected to the external voltage source, and Maxwell stress is generated between the carbon lubricating grease 12, which compresses the VHB film 11. Under the action of the pressure difference, the dielectric elastomer membrane 2 is further biased to one side of the unit negative pressure chamber 16. When the power is cut off, it is restored, realizing the volume change between the unit pumping chamber 8 and the dielectric elastomer membrane 2, thereby realizing the function of pumping fluid.

[0020] The pumping sealing layer 1 and the negative pressure sealing layer 3 are formed by silicone casting and curing or by 3D printing of soft materials.

[0021] VHB film 11 is obtained by stretching VHB tape of a certain thickness in a certain proportion in both directions equiaxially. The surface of VHB film 11 has a certain degree of stickiness and also has pre-tension stress.

[0022] The specific method of using this invention is as follows: The vacuum pump draws air from the negative pressure sealing layer 3, causing the dielectric elastomer membrane 2 to be biased into several unit negative pressure chambers 16 to form a dome structure, which blocks the hose 5 at the air extraction hole 15 to stabilize the negative pressure.

[0023] When the copper foil 13 is connected to the voltage source, the dielectric elastomer membrane 2 is further biased under the action of Maxwell stress, and the volume between the dielectric elastomer membrane 2 and several unit pumping chambers 8 increases. Under the action of atmospheric pressure, the fluid flows into the pump through the one-way valve 4.

[0024] When the power is cut off, the dielectric elastomer membrane 2 returns to its state before the power is applied. The volume between the dielectric elastomer membrane 2 and several unit pumping chambers 8 is restored. The fluid is forced out of the pump by the dielectric elastomer membrane 2 and flows out through the one-way valve 4, thus completing a pumping process.

[0025] As can be seen from this implementation, the soft pump of the present invention utilizes voltage to actively control the pumping output performance, which has the characteristics of rapid response, wide controllability range, and the ability to maintain pumping performance even when bent at large angles through micro-element structure design. It is suitable for drive devices in soft robots or wearable devices and has broad application prospects.

Claims

1. A bendable planar soft pump driven by a dielectric elastomer, characterized in that: It includes a pumping sealing layer (1), a dielectric elastomer membrane (2), a negative pressure sealing layer (3), a one-way valve (4), and some hoses (5); one end of the pumping sealing layer has a fluid inlet (6), and the one-way valve (4) is connected to the fluid inlet (6) through the hose (5). The hose (5) is bonded to the fluid inlet (6). The other end has a fluid outlet (7), and the one-way valve (4) is connected to the fluid outlet (7) through the hose (5). The hose (5) is bonded to the fluid outlet (7). The fluid flows through the one-way valve (4) to the fluid inlet (6), and then through the flow channels (9) between several unit pumping chambers (8) on the pumping sealing layer to the fluid outlet (7) and out through the one-way valve (4). The pumping sealing layer (1) and the dielectric elastomer membrane (2) are connected to each other. The dielectric elastomer film (2) is bonded through adhesive surfaces (10) and (14); the dielectric elastomer film (2) includes a VHB film (11), carbon grease (12) and copper foil (13). The carbon grease (12) is applied to both sides of the VHB film (11), and the copper foil (13) is adhered to the VHB film (11). The carbon grease (12) on both sides is in contact with the upper and lower copper foils (13) respectively. The dielectric elastomer film (2) is bonded to the negative pressure sealing layer (3) through adhesive surfaces (14) and (18). One end of the negative pressure sealing layer (3) is provided with an air extraction hole (15). The air extraction hole (15) is bonded to the hose (5). The air extraction hole (15) is connected to several negative pressure cavities (16) on the negative pressure sealing layer (3) through a flow channel (17).

2. The bendable planar soft pump driven by a dielectric elastomer according to claim 1, characterized in that: The pumping sealing layer (1) and the negative pressure sealing layer (3) are formed by silicone casting and curing or by 3D printing of soft materials.

3. The bendable planar soft pump driven by a dielectric elastomer according to claim 1, characterized in that: The VHB film (11) is obtained by equiaxial biaxial stretching of a certain thickness of VHB tape, has a certain pre-stress and undergoes elastic deformation under external force, and the surface of the VHB film (11) has a certain stickiness.

4. The bendable planar soft pump driven by a dielectric elastomer according to claim 1, characterized in that: Carbon grease (12) is a flexible electrode material. It is applied symmetrically on both sides of the VHB film (11) using a mask. The uncoated carbon grease (12) is the bonding contact surface (14).

5. A bendable planar soft pump driven by a dielectric elastomer according to claim 1, characterized in that: The copper foil (13) is bonded to the VHB film (11) and connected to the carbon grease (12) on both sides. The copper foil (13) is connected to the external power source.

6. A bendable planar soft pump driven by a dielectric elastomer according to claim 1, characterized in that: The unit pumping chamber (8) on the pumping sealing layer, the carbon grease (12) on the dielectric elastomer membrane, and the unit negative pressure chamber (16) on the negative pressure sealing layer are arranged in parallel.

7. A bendable planar soft pump driven by a dielectric elastomer according to claim 1, characterized in that: The dielectric elastomer film (2), the hose (5) and the pump sealing layer (1) and the negative pressure sealing layer (3) are bonded by silicone soft adhesive.

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