Transparent Soft Electrothermal Actuators with Integrated Cu Nanowire Heater for Soft Robotics

Soft actuators with high flexibility have received widespread attention. Here, a transparent electrothermal soft actuator is designed and manufactured via sandwiched copper nanowires (Cu NWs) between two kinds of flexible substrates with different thermal expansion characteristics (polyethylene-terephthalate (PET) and low-density polyethylene (LDPE)). In order to improve bending characteristics of the soft actuator, heating performance of heaters with different widths is studied, and the bending characteristics of strain gauges under different voltages are also studied. The fabricated soft actuator can produce a bend of 90 degrees and provide about 1 mN of force at a low voltage of 6 V. The application of this type of soft actuator is demonstrated toward biomimetic robotics, a two-finger flexible transparent gripper is designed, where two soft actuators are utilized to simulate the movements of human fingers and realizes the operation of picking and placing fine objects. In addition, the topography of the object can be feasibly observed during clamping process of the soft actuator with certain light transmittance, which is favorable for the soft gripper application.