3D printed smart elastomeric foam with force sensing and its integration with robotic gripper

Robotic grippers are extensively investigated as terminal actuators for gripping workpieces in robotic applications. Lately, implementing closed-loop force control for grippers to grip fragile workpieces securely is attractive. This paper aims to provide a dual-security solution combining gripping force control and stress-buffering capability. An integrated force-sensitive smart polydimethylsiloxane (PDMS) foam containing an embedded force-sensitive resistor (FSR) was designed and directly fabricated by 3D printing technology. The real-time force measurement was fed back into the control loop with proportional-integral (PI) rectification to precisely regulate the driving air pressure. In addition, the inherent stress plateau effect of the PDMS foam structure provides a constant stress buffer to absorb potential collision energy. The results show that the dual-security gripper with smart PDMS foam is able to precisely control the applied force and reliably grip fragile objects even in the presence of disturbances, enhancing the reliability of gripping applications.