Multi-function untethered actuator based on Ni-Ti alloy and polylactic acid

Soft actuators with the capability for stable and delicate grasping of soft objects without mechanical damage have attracted increasing attention. However, conventional soft actuators are bound by tethered power, which results in a difficulty in remote drive, and their main function is to grasp objects. Herein, a method for fabricating a soft untethered actuator with multi-function is proposed. The shape memory alloy embedded in the soft driver can change the shape of the actuator, besides, it can make the actuator produce a great force, while the polymer with specific melting point which enables the actuator has holding force. Various work stages of actuator (bending, operating, holding or releasing) can be switched by exploiting the mismatch in the bending stiffness of the shape memory alloy and polymer constituting the soft actuator, and we utilize these states to design different applications. The soft actuator will have more application prospects in soft robots, security system, health monitoring, and so on.