Mechanical hysterons with tunable interactions of general sign

Abstract

Hysterons are the basic units of hysteresis that underlie many of the complex behaviors of disordered matter. Recent work has sought to develop designs for mechanical hysterons, both to better understand their interactions and to create materials that respond to their mechanical environment in novel ways. Elastic structures including slender beams, creased sheets, and shells offer the requisite bistability for artificial hysterons, but producing and controlling interactions between such structures has proven challenging. Here we report a mechanical hysteron composed of rigid bars and linear springs, which has controllable properties and tunable interactions of general sign. We derive an approximate mapping from the system parameters to the hysteron properties, and we show how collective behaviors of multiple hysterons can be targeted by adjusting geometric parameters on the fly. Our results provide a basic step towards hysteron-based materials that can sense, compute, and respond to their mechanical environment.