Bioinspired design of stimuli-responsive artificial muscles with multiple actuation modes

Artificial muscles that can reproduce the functions and biomimetic motions of natural muscles are widely used to construct soft robots with applications in various fields. However, it is still challenging to develop stimuli-responsive artificial muscles with multiple-mode actuation. Inspired by the forearm muscles, we propose a new type of stimuli-responsive artificial muscles with multiple-mode actuation using liquid crystal elastomers (LCEs), named FILAMs (forearm muscle-inspired LCE-based artificial muscles). The proposed FILAMs consist of active LCE driving units, a passive silicone rubber flexible skeleton and two quick connectors. By selectively actuating different types of LCE driving units, the FILAMs can achieve multiple-mode actuation, such as twisting, bending, combined twisting and bending. We introduce prototypical designs for the FILAMs and demonstrate that they can be used as ‘building blocks’ to reconfigure different soft robots. Three kinds of soft robots are constructed to show extensive applications through the cooperation of a combination FILAMs, i.e. a soft assembly robot, a soft crawling robot, and a soft flexible wrist.