Development of a Soft Pneumatic Actuator with In-built Flexible Sensing Element for Soft Robotic Applications

Soft robotic is revolutionizing conventional robotics due to its numerous advantages such as safer interaction and compliant behavior. They are becoming increasingly popular in the medical field due to their safe human-robot interactions. Soft actuators are the main components of a soft robot. In the present work, a soft pneumatic actuator (SPA) is designed for soft robotic applications. The designed SPA is developed with an in-built flexible sensing element for measuring its deflection. The in-built sensing element has been fabricated using a soft composite material made from three ingredients i.e., polyvinylidene fluoride (PVDF), carbon nanofibers (CNF), and an ionic liquid (IL). The developed sensor is a piezo-resistive type sensor that provides feedback control based on the change in bending angle corresponding to its changing resistance. The designed SPA with an in-built sensor (SPAIS) has been fabricated using 3D printing and casting techniques with a commercially available silicone rubber material, namely Ecoflex-OO50. Finally, the developed SPAIS has been used to develop a soft robotic gripper with three fingers of SPAIS for grasping and holding of delicate objects of different shapes and sizes.