Self-Assembling Soft Climbing Robots, inspired by Army Ant Colonies.
Social insect colonies, like human societies, build some of the most complex and diverse physical structures to house their population, store their goods, and protect their young. One of the most incredible examples is structures made through self-assembly, out of the bodies of the insects themselves. Army ants (genus Eciton), for example, are able to form towers, bridges, rafts, and even their full nest (bivouacs) from their bodies. Unlike traditional human structures, these self-assembled structures are temporary and adaptable: army ant bridges and ramps form in response to congestion, repair when broken, change size based on traffic levels, and disassemble when no longer needed. The self-assembly constantly adapts itself to the environment.
The goal of the Eciton robotica project is to design a self-assembling robot swarm, capable of working independantly and together to create complex adaptive structures such as a bridge or a tower, using local rules inspired by army ant (Eciton hamatum) studies.
These natural systems inspire us to envision artificial ones operating on similar principles, with a swarm of independent agents acting together to build large-scale structures as needed, guided by reacting to the local environment. Robot swarms that could self-assemble could accomplish remarkable tasks, such as creating bridges to navigate complex terrain, plugs to repair structural breaches, or supports to stabilize a failing structure. Such systems could enable robots to operate in complex, unpredictable settings, such as in natural disaster areas, where human presence is dangerous or problematic. Robots forming temporary structures also would be reusable; as structures becomes unnecessary, robots can disassemble and become building blocks for new ones.
This new project has three parts: (1) Robot Design: We have designed a novel soft climbing robot, called Flippy, that uses a compliant cable-driven body and simple flipping locomotion to autonomously climb many surface angles and transition between planes, using only simple "touch-sensing" at the feet. The Flippy robot is designed to grip into velcro surfaces, and is also covered in velcro, thus allowing robots to climb over their mates to create organic structures without complex docking requirements. We continue to explore new designs inspired by the "messy" but strong self-assebled structures that army ants form. (2) Self-Assembly Algorithms: We are using physics-based simulators to study agent-based rules for adaptive bridge and ramp structures. (3) Army Ant Studies: Together with our biology collaborators, we travelled to Panama (2016) to conduct new experiments on army ant bridge and bivouac formation.
PEOPLE: Melinda Malley, Mike Rubenstein (now faculty@northwestern); biology collaborators Dr. Helen McCreery (JSMF Fellow) and Simon Garnier (faculty@NJIT); related work by Lucian Cucu and Julia Ebert.