Design and Experimental Validation of Woodwork-Inspired Soft Pneumatic Grippers

This paper presents a novel design concept of a pair of soft gripper hands that can establish a secure connection between them for bearing a large load with a low air pressure. The design was inspired by dovetail joints in carpentry that enable a tight, strong connection between two pieces of wood. We propose to mimic the dovetail joint mechanism by using soft robotic fingers that interlace to each other for secure connection. The work was motivated by the need for securing a connection between two soft robotic arms for holding a balance-impaired older adult in case of losing balance. First, the design principle of dovetail-like secure soft finger connection is presented, and its potential application to a portable fall prevention system is described. Details of the dovetail soft finger design, its rapid inflation method, and other implementation issues are then discussed. Through experiments of a proof-of-concept prototype, it is validated that the dovetail soft fingers can bear at least 18 kg of load with only 52 kPa of air chamber pressure filled in 250 ms of charging time. At the end, the proposed method is compared to alternative methods using a Pugh chart.