UC Santa Barbara

Robots are traditionally composed of rigid components for their strength and predictability while performing precise, powerful, controllable movements. However, the lack of deformability limits a robot’s capacity to passively adapt to changing tasks and environments. Conversely, soft robots intentionally incorporate material and geometric compliance to passively adapt to challenges. Soft robot performance can be further advanced by leveraging anisotropy; physical properties that are different in different directions.

In my work we use soft robotics with anisotropic properties to address a diverse array of robotic challenges. 1) We used gecko-inspired adhesives, an anisotropic compliant micro-structure which can apply high shear force with near-zero normal force, on a flexible belt in place of rigid gear teeth to create a low-cost, continuously variable transmission with high gear ratios. 2) We made a soft pneumatic gripper with fingers whose stiffnesses vary with direction and joint position to passively adopt a pinch or wrap grasp depending on the shape of the object it is to grasp. 3) We leveraged a woven fabric’s ability to stretch when pulled at 45° to its inelastic warp and weft directions to create a fabric pneumatic artificial muscle. 4) We advanced the design of a tip-extending vine robots, a device that is stiff radially but lengthens from its tip with little resistance when inflated, by creating a camera mount, retraction device, and steering method. 5) With a modified version of the isotropic vine robot concept, we used biologically inspired principles including tip extension and asymmetric, directional air fluidization to manipulate granular forces to enable robotic burrowing in sand. 6) And finally, we are exploring several planetary applications of self-anchoring by creating an anisotropic root-like anchor that requires more force to pull out of the ground than to grow deeper. I believe my work will have wide- ranging impacts on a variety of fields from medical devices and agricultural monitoring to industrial inspection and planetary exploration.