Design, Fabrication and Analysis of Soft Robotic Grippers based on Passive Layer Jamming

Abstract

Soft fingers with variable stiffness based on jamming principle have the characteristics of simple structure, convenient control, and rapid response, but is usually requires vacuum pressure to squeeze the particles or layered materials to produce stiffness changes. A novel passive variable stiffness soft finger based on the passive layer jamming principle was presented in this paper. The inflation chamber of the soft finger was bent and squeezes the outer wall of the jamming chamber. The squeezing force causes the jamming layer unit inside the jamming chamber to squeeze each other to generate friction, which causes stiffness changed. Besides, aiming at the previous manufacturing methods of double-chamber soft fingers, this work also proposes an “integrated molding” casting process based on the lost-wax casting method, which can realize the manufacturing of soft fingers through on casting without splice. The experimental results shown that the soft finger with passive layer jamming also has excellent grasping performance under the condition of reducing additional equipment (vacuum system).