Patterned\nAluminum/Polydimethylsiloxane-Laminated\nFilm for a Solvent-Driven Soft Actuator with Programmable and Multistable\nShape Morphing

Abstract

Recently,\nsoft actuators capable of deforming in predictable ways\nunder external stimuli have attracted increasing attention by showing\ngreat potential in emerging industries. However, limited efforts are\nbeing spent on the untethered actuators with multistable deformations.\nAlso, there is a lack of mechanically guiding design principles for\nmultistable structures. Here, the patterned aluminum/polydimethylsiloxane\n(Al/PDMS)-laminated films with surface wrinkles are fabricated by\nmagnetron sputtering the Al layer on the PDMS substrate. By tuning\nthe geometric parameters and surface constraints of the patterned\nAl/PDMS-laminated films, a series of solvent-driven actuators with\nmultiform stable configurations (such as monostable arc, multistable\ncylinder, and monostable/bistable spiral) are proposed. The deformation\nmechanism is revealed using a linear elastic theory. Combined with\nthe finite element analysis method, the deformations of Al/PDMS-laminated\nfilms with different surface constraints and geometric configurations\nare visually predicted. Besides, we modulate the deformation of different\nparts of the Z-shaped actuators by tuning the surface constraints\nin different regions of the Z-shaped Al/PDMS bilayer films to achieve\nmultiple stable deformations in a single actuator. The concept offers\na huge design scope for reconfigurable soft robots. Finally, two bionic\napplications are proposed to demonstrate the practical applications\nof the soft solvent-driven actuator based on the patterned Al/PDMS\nfilms in artificial muscles and bionic robotics. This work provides\na strategy for the design and fabrication of programmable and controllable\nsoft actuators, laying the foundation for a wide range of applications\nin smart materials.