A Variable Stiffness Spring–Sponge Composite Tube with Fast Response and Shape Recovery

Abstract

Abstract Soft robots have attracted more and more attention from researchers in the past decades, and multiple materials and methods have been studied to solve the conflict between strength and adaptability. This paper presents a novel composite tube comprising a spring and sponge, which can transform between stiffness and softness, and also proposes a corresponding novel method to alter the stiffness of the tube swiftly and reliably. Additionally, studies indicate that the tube exhibits shape‐recovery ability. The potential applications of the tube are illustrated in a coat of the supporting structure in the natural orifice transluminal endoscopic surgery instrument, a fixing device for human arthrosis and skeleton rehabilitation, and a variable stiffness multidirectional actuator.