In comparison with solid and fluid mechanics, the study of terramechanics, or the physics of granular materials more broadly, is far less understood. This is due to the tendency for granular materials to behave very differently (solid-like vs fluid-like) as a function of stress state, moisture content, and grain geometry, among other factors.  Recent years have seen the development of new reduced order models and simulation techniques to better describe the behavior of these materials. 

In the Interact Lab, we hope to build upon these types of approaches and further understand principles of granular interaction by applying them to novel robotic design. Specific functional interest areas include self-burrowing and anchoring, particularly in legged organisms and robots, as well as the grasping and manipulation of cohesive grains

Design of mechanisms and transmissions is a longstanding field of study, but most analysis assumes that such systems operate in dry and/or lubricated environments. However, mechanism design for interaction in heterogeneous environments, such as sands, powders, pebbles, etc. will be a critical requirement for robots to begin making inroads in such environments. Similarly, the introduction of cohesion or saturation in the media, common in most soils on earth, carries additional design challenges for waterproofing and sealing. 

We aim to develop new types of transmissions, as well as soft and multi-material mechanisms for operation in and around sands, soils, and detritus.

While the prior focus areas emphasize understanding of single-agent interaction, many biological systems such as social insects excavate complex subterranean structures in colonies consisting of thousands of individuals.  We are broadly interested in the strategies which allow for burrowing in confined and crowded conditions, as well as the inter-agent coordination (whether direct or indirect) that results in emergent structure formation.