Bioinspired Horizontal Self-Burrowing Robot

Abstract

Many organisms adopt well-evolved strategies and traits to facilitate burrowing/penetration in soils. Example features include the “dual-anchor” strategy used by razor clams and rotational drilling adopted by scarab beetle larva and some seed awns. Overall, underground burrowing requires overcoming resistances to advance forward and forming anchorage to prevent slip backward. Inspired by the aforementioned self-burrowing features, we designed a modular horizontal burrowing robot that features an extensible body and a rotatable tip. The robot was buried 7 cm below the surface of a bed of glass beads, and burrowed by cyclically alternating extension/retraction of the body segment, facilitated by the rotation of the tip. The burrowing performance of the designed robot was evaluated under different tip designs and control strategies. Insights into the general principles of burrowing in granular media were discussed by comparing to swimming in low Reynolds number fluids.