Signal Propagation in Resettable Mechanical Logic

Abstract Unconventional computing, such as mechanical1 and microfluidic logic circuits2, quantum gates3, and mechanical metamaterials4 create opportunities for embedded computation, which overcome the power5, package size, and environmental limitations of conventional electronics. Emerging micro-manufacturing capabilities6 with environmentally robust materials enable mechanical logic circuits miniaturization. Kinematically, bistable logic propagates binary signals through cascading gate displacement transitions. Energetically, the inter- and intra- node compliances are tuned for re-programmable signal propagation. Applications need computational architectures which integrate resettable signal propagation7–10, logical operation11–16, and signal storage17–19. While many researchers explore aspects of these elements1, 20–23, none consider energetic limits and propagation dynamics to evaluate and advance the field. Here, we show a generalized model and metrics, validated by experimental results, that enables the design of scale-independent, resettable, mechanical logic circuits. By studying propagation energy flows, we identified non-dimensional operating regimes in which signals propagate and resettable logic is possible. We provide deterministic design methods to evaluate future divergent topologies for displacement-based mechanical logic structures. Our results demonstrate the framework for designing densely integrated mechanical computation systems which harvest available ambient energy to propagate computational cascades. This logic responds to multi-dimensional environmental inputs and thus enables re-programmable, powerless, and embedded computation.