MIT researchers have 3D-printed modular metamaterial blocks, dubbed bifur-circuits, whose internal conductive routes stay electrically connected when the assembly is rotated, compressed, stretched, or bent. A multimaterial printer can build the units in one pass. The structure can sense which shape it has taken without extra external wiring.
That is a step past the group’s earlier auxetic metamaterial antennas, which only settled into three stretch states. Bifur-circuits use mechanical bifurcation: past a tipping point, connected blocks snap into extra stable poses around a pivot, and each new unit multiplies the combinations. Connecting and rotating neighbors closes a unique circuit between them, which is how the object reads its own configuration.
Lead author Marwa AlAlawi, a mechanical engineering graduate student, said the geometry is the point. “If we think of mechanical metamaterials as building blocks, then our work is one way to take advantage of their geometry to embed intrinsic intelligence into hardware, which could open many possibilities,” AlAlawi said.
The team compressed reconfigurable assemblies more than 10,000 times and saw no drop in electrical connectivity. They also wrote a construction and simulation tool that outputs printer instructions. Demos include a chair that becomes a table with storage and can flatten to stow, plus a controller that launches different games depending on its shape.
The paper, Bifur-circuits: Interactive and Modular Metamaterial Building Blocks Via Bifurcated Geometries, will be presented at the ACM Symposium on User Interface Software and Technology. Co-senior authors are Ticha Sethapakdi and Stefanie Mueller of MIT CSAIL’s Human-Computer Interaction Group, with collaborators at MIT, the University of Tokyo, and the University of Michigan. Funding included Japan’s Science and Technology Agency and the Bahrain Crown Prince International Scholarship Program.
Source: news.mit.edu
