Metamaterial unit-cell with Dual-Properties enabled by Instabilities

Abstract

Metamaterials have extraordinary properties due to their designed structure rather than their constituent materials. Increasingly, metamaterials are formed that demonstrate reprogrammable properties; here, a property can be altered using a conditional input, separate from the deformation input, to access the property. To achieve materialised control for the reprogramming of properties and to subsequently simplify the use of a metamaterial, we harnessed mechanical instabilities, firstly, to memorise deformation history, and secondly, to dictate deformation output. Metamaterials based on our unit-cell can adapt to deformation input and process this information without requiring active control. This paper presents a tunable design of a metamaterial unit-cell with dual-property deformation behaviour for which an axial strain is used as the input to access its output deformation, as well as the input to switch between modes. Characteristics of the mechanism are analysed using simulations and are validated with experiments. Applications exploiting features of the unit-cell are explored in reprogrammable material properties and materialised computation.