| With the development of smart textiles in the direction of self-actuating,sensing and multi-functional integration,soft actuators have broad application prospects in wearable devices,soft robots and bionic equipment.Among various stimulus,electrothermal actuators occupies an important position due to the advantages of easy adjustment of electrical signals,large strain rate,simple operation,and strong environmental adaptability.Choosing suitable actuating materials and simple preparation methods are of great significance to the research of soft actuators.However,current electrothermal actuators generally have the problems of small bending amplitude and actuating force,which limit the practical application of soft actuators.For this problem,the main research contents of this paper are as follows:(1)Aiming at the problems of insufficient self-actuating performance and poor adhesion of composite materials,a scheme using magnetron sputtering technology was proposed.Carbon fibers/polyimide composite film was used as the substrate,and Cu particle was deposited on the composite film by magnetron sputtering technology.Thus,the firmly deposited electrothermal actuators were obtained and the performance was tested.By controlling the processing time of magnetron sputtering,soft actuators with different thicknesses of Cu micro-layer were obtained.After magnetron sputtering treatment for 2 h,the average copper deposition thickness was 1.1 ?m,the square resistance range was 1?1.32 ?/sq,and the highest temperature of 214.8°C and the maximum bending angle of 88.8° could be obtained within 10 s under a voltage of 7 V,showing excellent fast response and large deformation performance.(2)In view of the improvement of self-actuating performance including response speed,deformation amplitude,actuating force,etc.,graphene was coated on the carbon fibers/polyimide composite substrate by the electrospray method to prepare skeleton soft actuators.As the skeleton supporting material,the carbon fibers played an important role in the working process of the actuators.The experimental results showed that when the voltage was 6 V,the non-skeleton soft actuator could obtain bending angle of 47° and actuating force of 1.86 m N;in contrast,the skeleton soft actuator can generate large bending angle of 112° and actuating force of 7.25 m N.The preparation method was simple and easy to operate,and the actuating force of the device was improved.(3)In order to develop the further practical application of soft actuators,through the processing design and assembly of the structure,the star-shaped,hand-shaped and leaf-shaped bionic devices that deform under electrothermal actuating and various soft robotics with different functions were constructed.For example,the gripper composed of graphene-based carbon fiber skeleton actuators could lift the sponge of 1.04 g and move,since the self-crawler moved forward by 50 mm in 227 s,and the self-actuating weightlifter lifted an object that was 13.5 times its own weight.Comparing with the non-skeleton actuators,the enhancement effect of carbon fiber on the performance of the soft actuators can be clearly observed.The prepared film-based electrothermal soft actuator has high self-actuating performance,and can be applied to fields such as soft robots,artificial muscles,and wearable devices.In summary,through the exploration of the method and the selection of materials,the copper deposition and the graphene-based soft electrothermal actuator were prepared,and the application in the bionic devices and flexible robotics was studied.The performance of the prepared soft actuators was improved,and it has wide application prospects. |
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