Reprogrammable Digital Metamaterials for Interactive Devices

We present digital mechanical metamaterials that enable multiple computation loops and reprogrammable logic functions, making a significant step towards passive yet interactive devices. Our materials consist of many cells that transmit signals using an embedded bistable spring. When triggered, the bistable spring displaces and triggers the next cell. We integrate a recharging mechanism to recharge the bistable springs, enabling multiple computation rounds. Between the iterations, we enable reprogramming the logic functions after fabrication. We demonstrate that such materials can trigger a simple controlled actuation anywhere in the material to change the local shape, texture, stiffness, and display. This enables large-scale interactive and functional materials with no or a small number of external actuators. We showcase the capabilities of our system with various examples: a haptic floor with tunable stiffness for different VR scenarios, a display with easy-to-reconfigure messages after fabrication, or a tactile notification integrated into users’ desktops.