A supertough electro-tendon based on spider silk composites

Liang Pan,Ming Wang,Fan Wang,Wan Ru Leow,Pingqiang Cai,Yong-Wei Zhang,Yuan Cheng,Dechang Li,Xiaodong Chen,Baohua Ji

doi:10.1038/s41467-020-14988-5

Abstract

Compared to transmission systems based on shafts and gears, tendon-driven systems offer a simpler and more dexterous way to transmit actuation force in robotic hands. However, current tendon fibers have low toughness and suffer from large friction, limiting the further development of tendon-driven robotic hands. Here, we report a super tough electro-tendon based on spider silk which has a toughness of 420 MJ/m3 and conductivity of 1,077 S/cm. The electro-tendon, mechanically toughened by single-wall carbon nanotubes (SWCNTs) and electrically enhanced by PEDOT:PSS, can withstand more than 40,000 bending-stretching cycles without changes in conductivity. Because the electro-tendon can simultaneously transmit signals and force from the sensing and actuating systems, we use it to replace the single functional tendon in humanoid robotic hand to perform grasping functions without additional wiring and circuit components. This material is expected to pave the way for the development of robots and various applications in advanced manufacturing and engineering.

Highlights

Compared to transmission systems based on shafts and gears, tendon-driven systems offer a simpler and more dexterous way to transmit actuation force in robotic hands
single-wall carbon nanotubes (SWCNTs) are often used for mechanical enhancement in many material systems[34,35,36,37,38]
SWCNT in this work can further improve the conductivity of Ssilk through electronic density transfer from PEDOT to SWCNT39,40

Summary

Introduction

Compared to transmission systems based on shafts and gears, tendon-driven systems offer a simpler and more dexterous way to transmit actuation force in robotic hands. Because the electro-tendon can simultaneously transmit signals and force from the sensing and actuating systems, we use it to replace the single functional tendon in humanoid robotic hand to perform grasping functions without additional wiring and circuit components. This material is expected to pave the way for the development of robots and various applications in advanced manufacturing and engineering. The electro-tendon makes from the Nephila pilipes spider dragline silk, single-walled carbon nanotube (SWCNT) and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) We show this electro-tendon can bend and stretch more than 40,000 cycles without any change in conductivity. When attaching to a pressure sensor and mounting on a 3D-printed human-like robotic finger, the electro-

Methods

Results

Conclusion