Development of self-sensing Ionic Polymer-Metal Composite soft robotic actuator integrated with gallium-indium alloy

Ionic Polymer Metal Composites (IPMC) have the ability to produce versatile types of deformations including bending and twisting [1]. This allows for the actuator to be used in applications where precise movement is needed. To make the IPMC a smart actuator, gallium-indium (GaIn) alloy is added to the actuator, adding a self-sensing feature to IPMC. The liquid alloy can be used as a strain gage within the IPMC, giving the actuator information to better understand its own movements to accurately reach the desired motion and location. An initial analysis was conducted using MATLAB to understand how the GaIn will deform with a point load at the free end of the prototype. Based on the code, the initial resistance is 14.7 Ω and after a point load of -0.005 N the new resistance becomes 74 Ω. It can thus be viewed that GaIn can be used in bending strain gage. An initial prototype was designed and fabricated using PDMS.