Study On The Mechanical Design And Fabrication Of Microstructured Materials/devices

Microstructured materials/devices can achieve excellent mechanical properties and rich functions through fine microstructure design,and have important applications in the fields of aerospace,biomedical and defense industry.With the rapid development of microstructure processing and preparation technologies such as additive manufacturing,the level of design and fabrication of complex delicate microstructures has been greatly improved,however,the level of accuracy of related technologies and the influence of preparation defects still need urgent attention.In this paper,we design and prepare programmable microstructure flexible actuators based on mechanical principles by integrating experiments,simulations and theoretical analysis,and investigate the effects of processing and fabrication defects on the mechanical behavior of typical microstructure materials,in order to provide references for the mechanical design,preparation and application of microstructured materials/devices.The main research contents and results are as follows:(1)Mechanical design and preparation of microstructured flexible actuators with programmable deformation modes.The bilayer soft actuator has the advantages of simple structure and easy preparation,but its deformation mode is relatively single due to structural limitations.In this paper,a polypyrrole(PPy,actuator layer)/polyethylene terephthalate(PET,inert layer)bilayer soft actuator was prepared by electrochemical deposition and adhesion transfer techniques,and the microstructure of the actuator layer was designed by laser cutting technique to realize the programmable deformation mode of the bilayer soft actuator.The soft actuator can respond to environmental humidity changes and produce designed torsional deformation.(2)The influence of microstructure design influences the deformation mode of the soft actuator and its underlying mechanism analysis.A humidity-controlled actuation and deformation characterization platform was built to monitor the deformation of the soft actuator under humidity control in real time.The actuation and deformation patterns of the soft actuator with different cutting angles under varied humidity were obtained.Further,finite element simulation and theoretical modeling analysis were carried out to explore the underlying mechanical mechanism.Finally,the cucumber-whisker-like climbing soft actuator,the integrally prepared soft gripper and the modular deformable soft actuator were designed and fabricated,demonstrating the wide application prospects of the microstructure soft actuator.(3)Study of the effects of processing and preparation defects on the mechanical properties of microstructured materials.Due to the development level of preparation technologies such as additive manufacturing,errors and defects are inevitable in the preparation of complex microstructured materials/devices.By taking three-dimensional(3D)printing-based preparation of lightweight and high-strength 3D Octet-truss lattice structure and Iso-truss lattice structure as examples,we numerically investigated the effects of two types of defects,namely rod cross-sectional size printing errors and rod missing,on the mechanical properties of microstructured materials.The results show that the mechanical properties of the microstructured materials are more sensitive to the missing defects of the rod,and the corresponding defect tolerance capacity is strongly and positively correlated with the number of super-stationary times of the nanolattice structures.