The rope-driven continuum robot (CDCR) is an important soft robot, which has the characteristics of light structure, safety and high degree of freedom. Works well in cramped and complex environments. Currently, fiber Bragg grating sensors commonly used in CDCR systems have high modulus, extremely low elongation, and lack of adhesion mechanisms, which limit the motion of soft robots and are prone to delamination with robots, which makes such rigid sensors unsuitable for integrated systems. . How to design flexible and stickable sensors for self-sensing and motion monitoring of CDCR remains a challenge.
Researcher Chen Tao and associate researcher Gao Guorong of the intelligent polymer material team of Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, cooperated with researcher Zhang Chi and senior engineer Zheng Tianjiang of the precision motion robot team, based on the two teams in the field of ion conductive gel (Adv. Mater, 2020, 32, 2004290; Nano Energy, 2021, 90, 106614, etc.) and research results in the field of CDCR (IEEE Access, 2019, 11, 174236; Symmetry, 2019, 11, 1158, etc.) The skin-like hydrogel sensor made of alginate/nanoclay polymer composite hydrogel realizes CDCR flexible self-sensing.
The introduction of the non-covalent cross-linked dynamic network structure enables the hydrogel to have good stretchability (1840%), self-adhesion (6.6 kPa adhesion strength) and self-healing properties. (stretching, compression, bending, torsion) for a wide range of sensitive responses, and adhering it as a skin-like sensor on the surface of the CDCR, the CDCR can obtain proprioception for sensing motion and external perception for sensing obstacles and traps. Further imitating the human sensory system, a closed-loop control system for regulating the bending of the CDCR can be constructed, and the closed-loop control of “actuating-sensing-feedback” can be constructed to guide the subsequent actuation. This study establishes an efficient approach for designing sensors and closed-loop systems for rope-actuated continuum soft robots.