Carangidae-imitated robotic fish based on DEMES structure and manufacturing method of carangidae-imitated robotic fish

Abstract

The invention discloses a carangidae-imitating robotic fish based on a DEMES structure and a manufacturing method thereof.The carangidae-imitating robotic fish comprises a driving unit (1), a fish head frame (2) and a tail fin (3), the front end of the driving unit (1) is connected with the fish head frame (2), the tail end of the driving unit (1) is connected with the tail fin, and the driving unit (1) comprises at least one pair of symmetrically-arranged DEMES bending actuators (4) and a connecting angle mechanism (5); the pair of connecting angle mechanisms (5) is symmetrically fixed to the outer side of the DEMES bending actuator (4) which is symmetrically arranged. The DEMES bending actuator (4) comprises a PET frame (6), a dielectric elastomer (7), a reinforcing piece (8), an electrode (9) and a wire, the PET frame (6) is made of a high-toughness PET sheet, the reinforcing piece (8) is made of a PET material, and the dielectric elastomer (7) is made of a 3M VHB acrylic acid series film. The device has the advantages of being high in propelling efficiency, good in position controllability, not prone to winding with aquatic organisms, compact in structure, fast in response and high in efficiency.

Description

Technical Field

[0001] This invention belongs to the field of flexible biomimetic robot technology, and particularly relates to a trevally-inspired robotic fish based on a dielectric elastomer minimum energy structure (DEMES), and also relates to a method for manufacturing the trevally-inspired robotic fish based on DEMES. Background Technology

[0003] Dielectric elastomers (DEs) are advanced elastomeric materials with high dielectric constants, capable of changing shape under an applied electric field. They quickly return to their initial shape after the electric field disappears. However, the application of dielectric elastomers in underwater robotic fish still faces many challenges. Dielectric elastomer actuators (DEAs) are a class of intelligent flexible materials with electroresponsive characteristics. They polarize under high voltage, exhibiting significant advantages such as light weight, large actuation strain, and fast response speed. Although the required excitation voltage typically exceeds kilovolts, the associated current is very small (milliamperes), making the battery module sufficient to meet the continuous operation requirements of the robotic fish. Furthermore, dielectric elastomer actuators possess low noise, a density close to that of water, and natural transparency, making them ideal propulsion materials for underwater robotic fish.

[0004] Based on their swimming methods, underwater flexible biomimetic robotic fish can be categorized into the following types: breaststroke type, tail fin propulsion type, water-pushing type, and pectoral fin oscillation type. Breaststroke type flexible biomimetic robotic fish use dielectric elastomer actuators as "robotic legs," propelling themselves forward by paddling backward. Tail fin propulsion type flexible biomimetic robotic fish use dielectric elastomer actuators as their tail fins, or drive the tail fin to oscillate, thus propelling themselves forward underwater. In water-pushing type flexible biomimetic robotic fish, multiple dielectric elastomer actuators are arranged in a ring structure. When the actuators are activated, water flows through the robotic fish's body, suspending it; when the actuators are deactivated, water flows around the body, causing it to float. In pectoral fin oscillation type flexible biomimetic robotic fish, dielectric elastomer actuators drive the pectoral fins to oscillate and propel themselves underwater.

[0005] Li constructed a frog-shaped flexible biomimetic robotic fish using four dielectric elastomer actuators as "frog legs," achieving a maximum movement speed of 132 mm / s. Inspired by eel larvae, Christianson created a transparent underwater biomimetic robotic fish using a three-segment fluid electrode dielectric elastomer actuator, achieving a maximum swimming speed of 1.9 mm / s and a Froude propulsion efficiency of 52%. Cheng designed a wireless flexible robotic jellyfish by casting six silicone fins onto a dielectric elastomer actuator, achieving a maximum movement speed of 5 mm / s. Zhang developed a wireless flexible biomimetic robotic fish by combining a dielectric elastomer actuator with two flexible undulating fins and a portable power source. Xu developed a dielectric elastomer actuator with a solid-liquid interpenetrating network structure and used it to create a flexible ray-like robotic fish, achieving a maximum swimming speed of 5.7 mm / s. Li has developed a wireless, flexible, biomimetic robotic fish that integrates a dielectric elastomer actuator, power supply, and remote control system. This allows the robotic fish to swim rapidly underwater via remote control. Inspired by the lionfish of the Mariana Trench, Li's team developed a deep-sea biomimetic robotic fish, which successfully completed testing at a depth of 10,900 meters in the Mariana Trench and can swim freely at a depth of 3,224 meters in the South China Sea. Godaba et al. developed a jellyfish robot using piezoelectric films. By deforming the film to change the volume of the air cavity, water is expelled from the body to generate propulsion.

[0006] Most of the underwater robotic fish mentioned above use a spiral propulsion method; however, this method has many drawbacks. On the one hand, spiral propulsion is inefficient and cannot meet the needs of long-term, long-distance underwater operations. On the other hand, its position controllability is poor, making it difficult to accurately locate and move in complex underwater environments, and it is also prone to entanglement with aquatic organisms, posing a potential threat to the underwater ecosystem. Summary of the Invention

[0008] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a DEMES-based robotic fish that features high propulsion efficiency, good position controllability, is not easily entangled with aquatic organisms, has a compact structure, fast response, and high efficiency.

[0009] Another object of the present invention is to provide a method for manufacturing the DEMES-based trevally-like robotic fish.

[0010] The objective of this invention and the solution to its main technical problem are achieved by the following technical solution: This invention discloses a robotic fish model of a trevally based on a DEMES structure, comprising a drive unit, a head frame, and a tail fin. The front end of the drive unit is connected to the head frame, and the rear end of the drive unit is connected to the tail fin. The drive unit includes at least one pair of symmetrically arranged DEMES bending actuators and connecting angle mechanisms. The pair of connecting angle mechanisms are symmetrically fixed to the outer sides of the symmetrically arranged DEMES bending actuators. The DEMES bending actuator includes a PET frame, a dielectric elastomer, reinforcing members, electrodes, and wires. The PET frame is a rectangle with a square-round central hole. The shape of the central hole is a rectangle with a semicircle between two semicircles, the diameter of which is the long side of the rectangle. The dielectric elastomer covers the PET frame. The reinforcing member is rectangular with a semicircular groove centered on its long side. The size of this semicircular groove is the same as the size of the semicircle of the central hole in the PET frame. A pair of reinforcing members are symmetrically arranged and attached to the dielectric elastomer along the semicircular edges of the central hole on both sides of the PET frame. Electrodes are applied to the dielectric elastomer at the corresponding positions of the central hole in the PET frame.

[0011] The symmetrically arranged DEMES bending actuators are symmetrically bent with the DEMES bending actuators centered, with one end of the two DEMES bending actuators bonded together and the other end symmetrically distributed on both sides of the bonded end.

[0012] The fish head frame is equipped with a buoy and a counterweight.

[0013] The present invention discloses a method for manufacturing a robotic fish modeled after a trevally based on a DEMES structure, comprising the following steps: (1) Fabrication of DEMES bending actuator a) The PET frame is made of high-toughness PET sheet, cut into a rectangle with a square-round center hole. The shape of the center hole is a rectangle between two semicircles, and the diameter of the semicircles is the long side of the rectangle. b) The reinforcing member is made of PET material and is laser-cut into a rectangle. A semi-circular groove is cut in the center of the long side. The size of the semi-circular groove is the same as the size of the semi-circle of the middle hole of the PET frame. c) The dielectric elastomer is 3M VHB acrylic film, cut to 1 / 4 of the pre-stretched size. The cutting tool is a die-cutting machine to avoid edge heat damage caused by laser cutting. d) The electrode material is conductive carbon with a volume resistivity of 0.1-1 Ω·cm; the lead-out electrodes are connected by copper foil tape with a thickness of 0.05-0.1 mm. e) Polytetrafluoroethylene insulated wires should be used. Silicone wires should be matched to the electrode spacing, and the insulation layer thickness should be 0.2-0.5mm. f) Pre-stretching of the dielectric elastomer is performed using a precision stretching fixture, with tension applied synchronously along the x and y axes; g) Before pasting the dielectric elastomer, wipe the film surface with isopropyl alcohol to remove oil and dust, and after drying, apply the adhesive evenly. When pasting the dielectric elastomer to the PET frame, use positioning fixtures to ensure that the center of the PET frame and the dielectric elastomer film are aligned. h) A pair of reinforcing members are attached to the dielectric elastomer and arranged symmetrically along the semi-circular edges of the center hole of the PET frame; i) The electrodes are applied by spraying in 2-5 coats onto the dielectric elastomer at the corresponding position of the center hole of the PET frame, with the total thickness controlled at 0.2-0.3 mm to ensure uniform coating without any missed areas. j) Conductive silver paste is used to bond the wires to the electrodes. The amount of paste should be enough to cover the core wires. After bonding, the wires are fixed with clamps. (2) Fabrication of the drive unit: a) The DEMES bending actuator is symmetrically bent at a certain angle in the center. Two DEMES bending actuators are bonded together at one end and symmetrically distributed on both sides of the bonded end at the other end. b) A pair of connecting angle mechanisms are symmetrically bonded and fixed to the outer side of the symmetrically arranged DEMES bending actuators; (3) The drive unit is connected to the fish head frame. The connection angle mechanism of the drive unit is bonded and fixed to the tail end of the fish head frame; (4) Connection between the drive unit and the tail fin The caudal fin is a low aspect ratio triangle and is glued and fixed to the tail end of the drive unit.

[0014] The above-mentioned method for manufacturing a trevally-like robotic fish based on the DEMES structure, wherein: in step (1) f), the dielectric elastomer pre-stretching is applied synchronously along the x and y axes to achieve 400%×400% pre-stretching, with an elongation ratio λ=4 and a stretching speed controlled at 5mm / min.

[0015] The above-mentioned method for manufacturing a trevally-like robotic fish based on a DEMES structure includes: in step (1) f), after the dielectric elastomer is pre-stretched, a fixed frame is used to clamp the edge of the dielectric elastomer film, and a silicone pad is pasted at the contact point between the fixed frame and the dielectric elastomer film.

[0016] The above-mentioned method for manufacturing a trevally-like robotic fish based on a DEMES structure, wherein the adhesive mentioned in step (1) g) is epoxy resin.

[0017] The above-mentioned method for manufacturing a trevally-like robotic fish based on a DEMES structure includes the following: in step (1) g), the dielectric elastomer described is bonded to the PET frame 6, and the bonding strength is tested to be 10-20 N / cm after curing. 2 .

[0018] The above-mentioned method for manufacturing a trevally-like robotic fish based on a DEMES structure, wherein: when the electrodes are coated on both sides of the dielectric elastomer film in step (1) i), the wire connection area should be avoided and a 5mm insulating edge should be reserved.

[0019] The above-mentioned method for manufacturing a trevally-like robotic fish based on a DEMES structure, wherein: the contact resistance between the wire and the electrode in step (1)j) is 10-50μΩ.

[0020] Compared with existing technologies, this invention has significant advantages and beneficial effects. As can be seen from the above technical solution, the core of this invention is the drive unit, which is symmetrically fixed to the outer sides of two symmetrically arranged DEMES bending actuators using a pair of connecting angle mechanisms. The front end of the drive unit is connected to the fish head frame, and the rear end is connected to the tail fin. This method ensures that the drive unit can effectively mimic the undulating movements of a fish's body and tail fin. The tail fin is connected to the drive unit, providing the necessary propulsion when the drive unit is activated. This invention employs a mid-fin and / or paired-fin (MPF) propulsion mode, mimicking the natural swimming pattern of fish. The drive unit uses a dielectric elastomer actuator to simulate the bending movements of a fish's trunk and tail fin, thereby improving the performance of the robotic fish. The dielectric elastomer minimum energy structure (DEMES) actuator can output an angle and consists of a pre-stretched dielectric elastomer film, a flexible polyethylene terephthalate (PET) substrate, and reinforcement. Due to the adhesive nature of the dielectric elastomer film, it can tightly bond with the PET substrate and reinforcement, resulting in a large output angle and fast response. By incorporating biomimetic design into the body structure of the robotic fish to match its deformation mode with that of the flexible drive unit, and establishing a coupling relationship between the swimming speed and drive parameters, the angle of the connection mechanism was optimized to (120°), improving propulsion efficiency by 12%. A frequency-speed matching model was established; at a drive frequency of 3Hz, the robotic fish achieved a swimming speed of 16.1 mm / s, a turning radius of 0.53 times its body length, excellent acceleration and deceleration performance, a swimming number Sw=0.085, and a motion power consumption COT=70.3. This invention achieves an integrated structure-drive-control design, suitable for low-speed, high-control scenarios. Due to the improved propulsion speed and more flexible trajectory control, the robotic fish of this invention can reach a maximum swimming speed of 8.6 mm / s. Therefore, this invention has high propulsion efficiency, good position controllability, and is less prone to entanglement with aquatic organisms. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the trevally-inspired robotic fish of the present invention; Figure 2 for Figure 1 Top view; Figure 3This is a schematic diagram of the drive unit. Figure 4 for Figure 3 Top view; Figure 5 This is a schematic diagram of a bending actuator structure; Figure 6 yes Figure 5 AA section view; Figure 7 This is a schematic diagram showing the connection between the drive unit and the fish head frame; Figure 8 for Figure 7 Top view; Figure 9 This is a schematic diagram showing the connection between the drive unit and the tail fin; Figure 10 for Figure 9 Top view.

[0023] Marked in the image: 1. Drive unit, 2. Fish head frame, 3. Tail fin, 4. DEMES bending actuator, 5. Connection angle mechanism, 6. PET frame, 7. Dielectric elastomer, 8. Reinforcing member, 9. Electrode, 10. Center hole, 11. Buoy, 12. Counterweight. Detailed Implementation

[0025] The following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a DEMES-based robotic fish and its manufacturing method according to the present invention.

[0026] Example 1: See Figure 1-2 A robotic fish modeled after a trevally based on a DEMES structure includes a drive unit 1 (for simulating fin movement), a head frame 2 (for support and reducing water resistance), and a tail fin 3 (propulsion is ultimately generated through the interaction between the tail fin and water). The front end of the drive unit 1 is connected to the head frame 2, and the tail end of the drive unit 1 is connected to the tail fin. (See...) Figure 3-4 The drive unit 1 includes at least one pair of symmetrically arranged DEMES bending actuators 4 and connecting angle mechanisms 5 (for fixing the initial angle of the DEMES bending actuators). The pair of connecting angle mechanisms 5 are symmetrically fixed on the outer sides of the symmetrically arranged DEMES bending actuators 4; the DEMES bending actuators 4 (see...) Figure 5-6The device includes a PET frame 6, a dielectric elastomer 7, reinforcing members 8, electrodes 9, and wires. The PET frame 6 is a rectangle with a square-round central hole 10. The shape of the central hole 10 is a rectangle between two semicircles, with the diameter of the semicircles being the long side of the rectangle. The dielectric elastomer 7 covers the PET frame 6. The reinforcing member 8 is rectangular, with a semicircular groove in the center of its long side. The size of the semicircular groove is the same as the size of the semicircle of the central hole 10 of the PET frame 6. A pair of reinforcing members 8 are symmetrically arranged and pasted on the dielectric elastomer 7 along the semicircular edges of the central hole 10 of the PET frame 6. The electrodes 9 are coated on the dielectric elastomer 7 at the corresponding positions of the central hole 10 of the PET frame.

[0027] The symmetrically arranged DEMES bending actuator 4 is a DEMES bending actuator that is symmetrically bent in the center, with one end of the two DEMES bending actuators 4 bonded together and the other end symmetrically distributed on both sides of the bonded end.

[0028] The fish head frame 2 is equipped with a buoy 11 and a counterweight 12.

[0029] Example 2: A method for manufacturing a robotic fish modeled after a trevally based on a DEMES structure includes the following steps: (1) Fabrication of DEMES bending actuator 4 (see Figure 5-6 ) a) The PET frame 6 is made of a high-toughness PET sheet with a thickness of 0.125mm. It is laser-cut into a rectangle with a square-round central hole 10 (ensuring that the edge of the central hole 10 is free of burrs). The shape of the central hole 10 is a rectangle between two semicircles, with the diameter of the semicircles being the long side of the rectangle and the width being 10mm. b) The reinforcing member 8 is made of 0.2mm thick PET material, which is laser-cut into a rectangle and a semi-circular groove is cut in the center of the long side. The size of the semi-circular groove is the same as the size of the semi-circle of the middle hole 10 of the PET frame 6. c) Dielectric elastomer (DE) 7 uses 3M VHB acrylic film with an original thickness of 1mm. It is cut to 1 / 4 of the pre-stretched size. The cutting tool is a die-cutting machine to avoid edge heat damage caused by laser cutting. d) Electrode 9 is made of conductive carbon to ensure a volume resistivity of 0.1 Ω·cm; the lead-out electrodes are connected by copper foil tape with a thickness of ≤0.05 mm. e) Polytetrafluoroethylene insulated wires should be used. Silicone wires should be matched with the electrode spacing. The insulation layer thickness should be 0.2mm to avoid high voltage breakdown. f) Pre-stretching of dielectric elastomer (DE) 7 is carried out using a precision stretching fixture. Tension is applied synchronously along the x and y axes to achieve 400%×400% pre-stretching (elongation ratio λ=4). The stretching speed is controlled at 5mm / min to avoid stress concentration that could cause the dielectric elastomer (DE) 7 film to tear. After pre-stretching, a fixing frame is used to clamp the edge of the dielectric elastomer (DE) 7 film. Silicone gaskets are attached to the contact points between the fixing frame and the dielectric elastomer (DE) 7 film to prevent excessive local pressure from damaging the dielectric elastomer (DE) 7 film.

[0030] g) Before bonding the dielectric elastomer (DE) 7, wipe the film surface with isopropyl alcohol to remove oil and dust. After drying, apply adhesive (epoxy glue) evenly. When bonding the dielectric elastomer (DE) 7 to the PET frame 6, use a positioning fixture to ensure that the center of the PET frame 6 and the dielectric elastomer (DE) 7 film are aligned. After curing, the bonding strength is tested to be 10 N / cm. 2 ; h) A pair of reinforcing members 8 are attached to the dielectric elastomer (DE) 7 and are symmetrically arranged along the semi-circular edges of the center hole 10 of the PET frame 6, with a spacing of 10mm.

[0031] i) The electrode 9 is applied by spraying in three coats onto the dielectric elastomer 7 at the corresponding position of the center hole 10 of the PET frame. The total thickness is controlled at 0.2 mm to ensure that the electrode is uniform and without any omissions. When coating the electrode with the dielectric elastomer (DE) 7 film on both sides, the wire connection area should be avoided and a 5 mm insulating edge should be reserved to prevent short circuits.

[0032] j) The wire and electrode 9 are bonded with conductive silver paste. The amount of paste should be enough to cover the core wire. After bonding, fix it with a clamp to ensure that the contact resistance is 10μΩ.

[0033] (2) Fabrication of the drive unit (see Figure 3-4 ): a) The DEMES bending actuator 4 is symmetrically bent at a certain angle in the center. Two DEMES bending actuators 4 are bonded together at one end and symmetrically distributed on both sides of the bonded end at the other end, forming a symmetrical joint structure that can be bent as a whole. This symmetrical arrangement makes it possible for the two DEMES bending actuators 4 to produce alternating bending motions when driving voltages with opposite phases are applied to them, thereby simulating the swimming posture of a fish swaying from side to side.

[0034] (b) A pair of connecting angle mechanisms 5 are symmetrically bonded and fixed to the outer side of the symmetrically arranged DEMES bending actuators 4. This ensures that the initial angle of each symmetrically arranged DEMES bending actuator 4 remains constant at 30°, 60°, 90°, or 120°. By changing the angle of the connecting angle mechanisms 5 (60°, 120°, 180°, or 240°, etc.), the output performance (such as angle variation and force generation) of the DEMES bending actuators 5 can be optimized. Tests have shown that the force generated is greatest when the angle of the connecting angle mechanism 5 is 120°, with a 12% improvement in propulsion efficiency compared to 90°. The angle variation is greatest at 180°. The drive unit outputs the maximum oscillation amplitude at a frequency of 3 Hz.

[0035] (3) The drive unit is connected to the fish head frame (see Figure 7-8 ) The head of the connecting angle mechanism 5 of the drive unit 1 is bonded and fixed to the tail end of the fish head frame 2 (head) made of CFRP (carbon fiber reinforced composite material); the CFRP fish head frame 2 provides the necessary structural support and rigidity, and at the same time, due to its lightweight and high strength characteristics, it helps to reduce water resistance and overall weight.

[0036] (4) The drive unit is connected to the tail fin (see Figure 9-10 ) The caudal fin 3 is a low aspect ratio triangle, bonded and fixed to the tail end of the drive unit 1. The shape of the caudal fin 3 is crucial for propulsion efficiency. Referring to fish biology, the caudal fin 3 is shaped into a low aspect ratio triangle to generate maximum amplitude at the end of the swing, thereby achieving better propulsion. The bending motion of the drive unit 1 is directly transmitted to the caudal fin 3, causing it to swing. The propulsion force is ultimately generated through the interaction between the caudal fin 3 and the water.

[0037] Example 3: A method for manufacturing a robotic fish modeled after a trevally based on a DEMES structure includes the following steps: (1) Fabrication of DEMES bending actuator 4 (see Figure 5-6 ) a), b), and c) are the same as in Example 2; d) The electrode material is conductive carbon with a volume resistivity of 1 Ω·cm; the lead-out electrodes are connected by copper foil tape with a thickness of 0.05 mm. e) Polytetrafluoroethylene insulated wires should be used. Silicone wires should be matched with the electrode spacing. The insulation layer thickness should be 0.5mm to avoid high voltage breakdown. f) Same as Example 2 g) Before bonding the dielectric elastomer (DE) 7, wipe the film surface with isopropyl alcohol to remove oil and dust. After drying, apply epoxy adhesive evenly. When bonding the dielectric elastomer (DE) 7 to the PET frame 6, use positioning fixtures to ensure that the center of the PET frame 6 and the dielectric elastomer (DE) 7 film are aligned. After curing, the bonding strength is tested to be 20 N / cm. 2 ; h) Same as Example 2.

[0038] i) The electrode 9 is applied by spraying in two coats onto the dielectric elastomer 7 at the corresponding position of the center hole 10 of the PET frame. The total thickness is controlled at 0.2 mm to ensure that the electrode is uniform and without any omissions. When coating the electrode with the dielectric elastomer (DE) 7 film on both sides, the wire connection area should be avoided and a 5 mm insulating edge should be reserved to prevent short circuits.

[0039] j) The wire and electrode 9 are bonded with conductive silver paste. The amount of paste should be enough to cover the core wire. After bonding, fix it with a clamp to ensure that the contact resistance is 50μΩ.

[0040] The rest is the same as in Example 2.

[0041] Example 4: A method for manufacturing a robotic fish modeled after a trevally based on a DEMES structure includes the following steps: (1) Fabrication of DEMES bending actuator 4 (see Figure 5-6 ) a), b), and c) are the same as in Example 2; d) The electrode material is conductive carbon with a volume resistivity of 0.5 Ω·cm; the lead-out electrodes are connected by copper foil tape with a thickness of 0.1 mm. e) Polytetrafluoroethylene insulated wires should be used. Silicone wires should be matched with the electrode spacing. The insulation layer thickness should be 0.3mm to avoid high voltage breakdown. f) Same as Example 2 g) Before bonding the dielectric elastomer (DE) 7, wipe the film surface with isopropyl alcohol to remove oil and dust. After drying, apply epoxy adhesive evenly. When bonding the dielectric elastomer (DE) 7 to the PET frame 6, use positioning fixtures to ensure that the PET frame 6 and the center of the dielectric elastomer (DE) 7 film are aligned. After curing, the bonding strength is tested to be 15 N / cm. 2 ; h) Same as Example 2.

[0042] i) The electrode 9 is applied by spraying in 5 coats onto the dielectric elastomer 7 at the corresponding position of the center hole 10 of the PET frame. The total thickness is controlled at 0.3 mm to ensure that the electrode is uniform and without any omissions. When coating the electrode with the dielectric elastomer (DE) 7 film on both sides, the wire connection area should be avoided and a 5 mm insulating edge should be reserved to prevent short circuits.

[0043] j) The wire and electrode 9 are bonded with conductive silver paste. The amount of paste should be enough to cover the core wire. After bonding, fix it with a clamp to ensure that the contact resistance is 25μΩ.

[0044] The rest is the same as in Example 2.

[0045] The above are merely preferred embodiments of the present invention and do not impose any limitations on the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from any technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A DEMES structure-based carangiform robot fish, characterized in that: The fish robot comprises a driving unit (1), a fish head frame (2), and a tail fin (3), the front end of the driving unit (1) is connected with the fish head frame (2), and the tail end of the driving unit (1) is connected with the tail fin, wherein the driving unit (1) comprises at least one pair of symmetrically arranged DEMES bending actuators (4) and connecting angle mechanisms (5), one pair of the connecting angle mechanisms (5) are symmetrically fixed on the outer side of the symmetrically arranged DEMES bending actuators (4); the DEMES bending actuator (4) comprises a PET frame (6), a dielectric elastomer (7), a reinforcing member (8), an electrode (9), and a wire, the PET frame (6) is a rectangle with a square and circular central hole (10), the shape of the central hole (10) is a rectangle between two semicircles, and the diameter of the semicircle is the long side of the rectangle; the dielectric elastomer (7) is covered on the PET frame (6), the reinforcing member (8) is a rectangle, and a semicircular groove is arranged in the middle of the long side, the size of the semicircular groove is the same as that of the semicircle of the middle hole (10) of the PET frame (6), and one pair of the reinforcing members (8) are symmetrically arranged and pasted on the dielectric elastomer (7) along the semicircular edge positions of the two sides of the central hole (10) of the PET frame (6); the electrode (9) is coated on the dielectric elastomer (7) at the corresponding position of the central hole (10) of the PET frame.

2. The DEMES structure based jacks-like robot fish of claim 1, wherein: The symmetrically arranged DEMES bending actuator (4) is symmetrically bent in the middle, and two DEMES bending actuators (4) are bonded together at one end and symmetrically distributed on the two sides of the bonded end.

3. The DEMES structure based carangiform robot fish according to claim 1 or 2, characterized in that: The fish head frame (2) is provided with a float (11) and a counterweight (12).

4. A manufacturing method of a DEMES structure-based carangidae robot fish, comprising the following steps: (1) manufacturing of the DEMES bending actuator (4) a) the PET frame (6) is selected from high-toughness PET sheet, and is cut into a rectangle with a square and circular central hole (10), and the shape of the central hole (10) is a rectangle between two semicircles, and the diameter of the semicircle is the long side of the rectangle; b) the reinforcing member (8) is made of PET material, is cut into a rectangle by laser, and a semicircular groove is cut in the middle of the long side, and the size of the semicircular groove is the same as that of the semicircle of the middle hole (10) of the PET frame (6); c) the dielectric elastomer (7) is selected from 3M VHB acrylic film, is cut according to 1 / 4 of the size after pre-stretching, and a die-cutting machine is used as a cutting tool to avoid edge thermal damage caused by laser cutting; d) the electrode (9) is made of conductive carbon, and the volume resistivity is 0.1-1 Ω·cm; copper foil tape is used to connect the lead electrode, and the thickness is 0.05-0.1 mm; e) the wire is selected from polytetrafluoroethylene insulated wire, and the silicone wire needs to match the electrode spacing, and the thickness of the insulating layer is 0.2-0.5 mm; f) the pre-stretching of the dielectric elastomer (7) is carried out by using a precision stretching tool to synchronously apply tension along the x and y axes. g) Before the dielectric elastomer (7) is pasted, isopropyl alcohol is used to wipe the surface of the film to remove oil and dust, and after drying, adhesive is evenly applied. When the dielectric elastomer (7) is pasted to the PET frame (6), positioning fixtures are used to ensure that the PET frame (6) is aligned with the center of the dielectric elastomer (7) film; h) A pair of reinforcing members (8) are pasted on the dielectric elastomer (7) and symmetrically arranged along the semicircular edge positions of the center hole (10) of the PET frame (6); i) The electrode (9) is applied by spraying method, and is applied to the dielectric elastomer (7) at the corresponding position of the center hole (10) of the PET frame in 2-5 times, with the total thickness controlled at 0.2-0.3 mm, to ensure uniform electrode without missing coating; j) The contact resistance between the wire and the electrode (9) is 10-50 μΩ. (2) Preparation of the driving unit: a) The DEMES bending actuator (4) is symmetrically bent at a certain angle, and the two DEMES bending actuators (4) are bonded together at one end and symmetrically distributed on both sides of the bonded end; b) A pair of connection angle mechanisms (5) are symmetrically bonded and fixed to the outer side of the symmetrically arranged DEMES bending actuators (4); (3) Connection of the driving unit and the fish head frame The connection angle mechanism (5) of the driving unit (1) is bonded and fixed to the tail end of the fish head frame (2); (4) Connection of the driving unit and the tail fin The tail fin (3) is a low-aspect-ratio triangle and is bonded and fixed to the tail end of the driving unit (1).

5. The method of claim 4, wherein the method further comprises: forming a first pair of pectoral fins on the first side of the body; and forming a second pair of pectoral fins on the second side of the body. In step (1) f), the dielectric elastomer (7) is pre-stretched along the x and y axis directions simultaneously to achieve a pre-stretching of 400% x 400%, with an elongation ratio λ = 4, and the stretching speed is controlled at 5 mm / min.

6. The method of claim 4, wherein the method further comprises: forming a first pair of fins on the first side of the body; and forming a second pair of fins on the second side of the body. In step (1) f), after pre-stretching, a fixed frame is used to clamp the edges of the dielectric elastomer (7) film, and a silicone gasket is pasted at the contact between the fixed frame and the dielectric elastomer (7) film.

7. The method of claim 4, wherein the method further comprises: forming a first pair of pectoral fins on the first side of the body; and forming a second pair of pectoral fins on the second side of the body. In step (1) g), the adhesive is epoxy glue.

8. The method of claim 4, wherein the method further comprises: providing a DEMES structure; and providing a fish tail structure. The dielectric elastomer (7) described in g) of step (1) is pasted with the PET frame (6), and the pasting strength is 10-20 N / cm after curing 2 .

9. The method of claim 4, wherein the method further comprises: providing a DEMES structure; and providing a fish tail structure. In step (1) i), when the dielectric elastomer (7) film is coated with electrode 9 on both sides, the wire connection area needs to be avoided, and a 5 mm insulation edge is reserved.

10. The method of claim 4, wherein the method further comprises: providing a DEMES structure; and providing a fish tail structure. In step (1) j), the contact resistance between the wire and the electrode (9) is 10-50 μΩ.

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