Embodied Behavior of Plant Roots in Obstacle Avoidance

Abstract

Plant roots are a new paradigm for soft robotics. Study of embodied behavior in roots may lead to the implementation of movements guided by structural deformations and to the use of sensors and actuators as body parts. In this work the obstacle avoidance in roots and its interplay with the gravitropism were studied both from biological and robotic viewpoint. Living roots resulted to achieve the maximum pushing force on an obstacle before starting circumnavigation (30 mN in 100 min), thus indicating the existence of a triggering threshold. Tip-to-obstacle angle (20°) was not influenced by the gravity. A robotic mockup capable to bend like living roots was build on the basis of current knowledge and our results on obstacle avoidance behavior. Exploitation of morphological features and passive body deformation resulted to be useful for implementing a simplified control of the robot during gravitropism and obstacle avoidance.