Preparation And Actuation Characteristics Study Of Twisted And Coiled Fiber-based Artificial Muscles

Artificial muscles refer to new materials,actuators or driving devices used to imitate natural muscles.They can sense external stimuli and contract,expand or rotate within a component,thereby deriving other complex types of movement.Compared with traditional rigid drives,twisted and coiled fiber-based artificial muscles have higher flexibility,versatility and power density,can better imitate the movement of human muscles,and have gradually become a hot spot for scientists.This paper focuses on the preparation,actuation characteristics,and theoretical models of twisted and coiled fiber-based artificial muscles.The main results are as follows:1.Based on the artificial muscle twister designed by Semochkin,a new generation of artificial muscle twister was developed.The twister has good structural stability,which significantly improves the success rate of preparing artificial muscles,and the artificial muscles have the same specifications and better actuation characteristics.Using this device,a series of twisted and coiled fiber-based artificial muscles were prepared by using nylon 6 fibers.2.Using instruments such as thermal imagers and displacement sensors,an experimental platform to study the actuation characteristics of artificial muscles was built.Using this platform,the actuation characteristics of nylon 6 fiber artificial muscles were studied.The results showed that as the input power increased,the actuation efficiency increased;when the input power is the same,the larger the cross-sectional area of the artificial muscle,the lower the actuation efficiency;the greater the load weight,the higher the actuation efficiency.Through tensile,torsional and nanoindentation experiments,the elastic modulus and shear modulus of nylon 6 fiber were measured,which laid the foundation for the analysis of the actuation characteristics of artificial muscles.3.Based on the method of multi-level structure analysis,a continuous medium mechanical model for explaining the actuation characteristics of twisted and coiled fiberbased artificial muscles is proposed.The model was used to analyze the effects of fiber deflection angle,spiral diameter and other structural parameters on the actuation performance of artificial muscles.The relationship between actuation strain and temperature was predicted,which was in agreement with the experimental results.The analysis shows that in the homo-chiral structure,as the fiber deflection angle increases,the contraction rate of the artificial muscle increases first and then decreases,while the result of the hetero-chiral structure is opposite;as the spiral diameter increases,the actuation effect is enhanced,and the carrying capacity is weakened.