Flexible Gripper Manufacturing And Simulation Based On 3D Printing Shape Memory Polymer

As stimulus-sensitive smart materials,shape memory polymers(SMPs)is able to respond to specific external stimuli,from pre-fixed temporary form to the initial state automatically.With the support of 3D printing technology,shape memory polymer molding is more rapid and convenient,and the structure is more precise and meticulous.Since that,SMPs has been widely used in intelligent material additive,biomedicine,flexible robot manufacturing and other cutting-edge fields.Shape memory polymer composites with special properties obtained by material additive technology are often limited by the type of 3D printing and will change the properties of shape memory polymer to some extent.Using electromechanical control techniques,SMPs can flexibly retain their own characteristics while rapidly applying variable external stimuli and providing accurate deformation.Therefore,the combination of 3D printing technology and electromechanical control technology can open up a broader practical application for SMPs.In this paper,through stereo lithography apparatus,the 1-way shape memory polymer tBAco-BDDA is successfully printed.Tert-Butyl acrylate monomer were synthesized with 1,4-bis(acryloyloxy)butane crosslinker and UV photoinitiators Phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.The effects of different components on the forming effect and shape memory were studied,it was found that the shape memory polymer with good shape memory properties and complete morphology could only be printed with the addition of 1.0wt% to 1.5wt% BAPO.TBA-co-BDDA with 10wt%BDDA crosslinker can show relatively ideal shape memory property and has a long memory cycle life and rapid shape transformation speed.In order to explore the practical application of intelligent SMP control in 3D printing,tBA-coBDDA based on 3D printing was used to realize the clamping action respectively with micro motor and SMP's direct response deformation,and the comparison was made.A flexible circuit is implanted to control local stimulation,as well as feedback and maintain a constant clamping force.This gripper can hold nearly 20 times of its own weight while keeping the temporary shape basically unchanged.In order to study the movement process of this gripper,the finite element numerical simulation method based on viscoelastic theory was used to simulate a grasping cycle.The simulation results are consistent with the experimental results.These findings show that the 3D printed tBA-co-BDDA has excellent shape memory performance,convenient molding and other advantages.The driving mode of intelligent gripper designed by electromechanical control technology is compared and the rationality of gripper design is verified by finite element numerical simulation.