Multifunctional Soft Actuators Based on Anisotropic Paper/Polymer Bilayer Toward Bioinspired Applications

Designing artificial muscle actuators with diversely complex deformation and multifunction is crucial to the soft robots and their bioinspired applications. Herein, by combing the hygroexpansion and thermal expansion commonly existed in nature, electrically driven paper-based bilayer actuator is fabricated by a simple printing method. This actuator exhibits large (270 degrees) and anisotropic deformation coupled with features of low-cost, superior stability, and additional reversible color-change function. More importantly, the tailoring and heat setting are used to further design the actuator shape, thus obtain multiform deformation (bending, elongation, and folding), and more complicated deformation similar to the arm motion. Based on these actuators, variously bioinspired motions can be constructed. Inspired by the structure of the crystalline lens and ciliary muscle in human eyeball, a biomimetic lens which can change the focal length under electrical stimulation is fabricated. Moreover, W-shaped robotic arm for manipulating microliquid in 3D direction and catapulting the object into air, in-pipe spiral robotic arm for pushing objects out of the pipe, and artificial snake capable of deformation and color-change simultaneously, are also fabricated. This paper-based actuator together with bioinspired design may open new perspective on the multifunctional smart robots and biomimetic devices.