Design, Fabrication and Analysis of a Inchworm-Inspired Soft Crwaling Robot Driven by Tensegrity

Inspired by the characteristics of inchworms’ movement, a soft crawling robot with symmetrical annular scale pairs driven by tensegrity is proposed. Two ring-shaped scales that are made of different materials can be combined into an annular scale pair to produce high and low friction to mimic the bristles of the inchworms. The tensegrity is composed of the constringent spring embedded in silicone rubber as strut and the rope driven by the motor as cable. The tensegrity achieves reciprocating telescopic motion driven by the motor, which drives the annular scale pair to deform and form different angles between the scale pair and the contact surface. Due to the difference of friction coefficient between different materials and surface, the resultant force which is the low friction force from the high friction force drives the crawling robot to move in the intended direction, and the velocity of its motion is related to the difference of coefficient between different materials and surface. Besides, the electronic control system placed inside the soft body to realize fully untethered. The maximum crawling speed and crawling angle are 2.5 mm/s and 10°, respectively.