A facile method for fabricating humidity-sensitive bilayer actuators with programmable deformation

It has long been interested in controlling the directional deformation of soft actuators. While certain efforts have been made in recent years, it is still desired to develop methods for fabricating soft actuators with programmable deformation. Here we developed a facial method to fabricate humidity-sensitive bilayer actuators with patterned surface for programmable deformation. We applied laser cutting to structurally pattern the active layer made of polypyrrole (PPy), which was then transferred to an inert polyethylene terephthalate (PET) tape to form a bilayer actuator. Both numerical and experimental studies verified the humidity-sensitive and programmable twisting behaviors of the patterned bilayer actuators. The bilayer actuators were further designed to both mimic the spiral winding behavior of a cucumber vine and fold to form an origami structure. The developed method is readily available and can be extended to other types of soft actuators, holding promises in application areas such as smart materials and structures.

Automated summary

This study developed a method to fabricate humidity-sensitive bilayer actuators with programmable deformation. Laser cutting was used to pattern the active layer made of polypyrrole (PPy), which was then transferred to an inert polyethylene terephthalate (PET) tape to form a bilayer actuator. Numerical and experimental studies confirmed the humidity-sensitive and programmable twisting behaviors of the patterned bilayer actuators. The developed method can be widely applied to other types of soft actuators and holds promises in areas such as smart materials and structures.