Soft Robots using Muscle-like Composite Actuators

Liquid crystal elastomers (LCEs), known for their reversible and anisotropic deformation, are promising candidates as embedded intelligent actuators in soft robots. Using an extrusion process, meter-long LCE composite filaments that are responsive to both infrared light and electrical fields are fabricated. When a small quantity of cellulose nanocrystals (CNCs) is incorporated to facilitate the alignment of liquid crystal molecules along the long axis of the filament, and 2 wt% carbon nanotubes (CNTs) is introduced, the mechanical property of filaments is improved and fast electrothermal response is demonstrated. The maximum work capacity of 38 J kg−1 is achieved, comparable with that of the mammal skeletal muscle. When the filaments are laid into arbitrary patterns for shape transformation or integrated in different robotic systems, we demonstrate a photoresponsive hopping unicorn, an electrothermally responsive flying eagle, and a multifunctional swing set.