A Soft Continuum Robotic Arm with a Climbing Plant-Inspired Adaptive Behavior for Minimal Sensing, Actuation, and Control Effort

A key challenge in designing soft continuum robotic arms is the realization of intelligent behavior while minimizing sensing, actuation, and control effort. This work investigates how soft continuum arms can benefit from mimicking the distribution of flexural rigidity of searcher stems in climbing plants to accomplish this goal. A modeling approach is presented to tune both the structural design and the tactile sensor design of a soft continuum arm inspired by the flexural rigidity distribution of Mandevilla cf. splendens’ searcher stems. The resulting soft continuum arm, named Mandy, can detect suitable supports along its length and twining around them using a single sensor and actuator. Through simulations and experiments, it is shown such behavior cannot be achieved with a soft continuum arm possessing uniform structural stiffness and a standard tactile sensor design. Thus, the significance of investing greater effort in structural design, leveraging biological data, to improve the design of soft continuum arms with more compact actuation and sensing hardware, is highlighted.