Architecture Design And Application Research For Eletro-actived Shape Memory Composites Based On Nano-Silver

Electro-active shape memory composites(E-SMCs)are a class of intelligently responsive conductive composites that undergo a transition from temporary shape to initial shape under external driven voltage.However,the current research on E-SMCs is still in the basic stage,and there are still some disadvantages such as high driven voltage and irreversible deformation,resulting in the limited application range.How to improve the conductivity of E-SMCs under the premise of ensuring shape memory effect and prepare self-responding E-SMCs with bidirectional deformation still has great challenges.Therefore,this research focuses on the design and performance of E-SMCs filler and flexible matrix network,and the structural design and application of self-responding flexible acutator based on E-SMCs,providing a theoretical basis for low-voltage driven E-SMCs and intelligent flexible acutator based on E-SMCs.Low voltage driven E-SMCs at ultra-low filler content are realized by designing 3D conductive networks in the shape memory polymer.The AgNWs/MFs/SMEP composites with uniform and stable 3D AgNWs conductive networks were prepared by dip-coating and vacuum casting process using MFs as template.AgNWs/MFs have good mechanical strength,excellent electrical conductivity and electrical resistance stability.After 5 dip-coating cycles,the electrical conductivity reaches 25.8 S/cm,and the loss is 0.12%after 5000 compressing cycles of 50%deformation.The conductivity of AME with 0.8 wt%AgNWs is as high as 25.6 S/cm,and it returns to the initial shape(shape recovery rate of 99%)within 25 s at 3 V,and has good reusability.Flexible low voltage driven E-SMCs with the function of strain sensing are achieved by the design of interpenetrating network of SMP matrix and the"sandwich"structure.PCL/PUA flexible shape memory materials(FSMP)were synthesized by melt blending and UV curing and the PAP composites were prepared by spraying AgNWs and casting PCL/PUA again.FSMP with 25%PCL has excellent shape memory effect(shape fixing rate is 99%)and the conductivity of PAP composites is 17.5 S/cm when AgNWs content is 2.5wt%.As a result,the composites can complete the recovery process within 25s at 2V.The"sandwich"structure provides a relatively stable conductivity,while it also has response to strain.PAP has a stable sensitivity(GF=0.66),low response time(183 ms),and good deformation resolution.Combining the shape deformation and strain sensing,the PAP with curved initial shape was applied to the grasp and release action by setting different temporary shapes and distinguish between different weights by the resistance change at the same time.The reversible deformation and bending sensing of E-SMCs are realized by designing triple-layer structure of matrix.The conductive layer of AgNPs as a connection layer was prepared by silver mirror reaction.PVA with hygroscopic deformation ability and PCL/PUA(FSMP)shape memory effect were used to prepare flexible PAF film,which can be driven reversibly and continuously under switch of wet-electric and has bending sensing function.The PAF film with 6 mol/m~2 AgNPs has excellent conductivity(surface resistance is 73.5 m?/sq).When the thickness ratio of cPVA to FSMP layer is 1:3,PAF has excellent reversible deformation performance and good strain sensing performance(GF=1.56),which can be bent within 30s in humid atmosphere and recovered within 10s at 2V.Therefore,the flexible acutator based on PAF has the ability to sense objects in real time and complete the position transfer of target objects(including grabbing and releasing actions),which is expected to be applied in the field of intelligent electronic devices such as soft robots.