Multistable Mechanical Metamaterials: A Brief Review

Over the past decade, multistable mechanical metamaterials have been widely investigated because of their novel shape reconfigurability and programmable energy landscape. The ability to reversibly reshape among diverse stable states with different energy levels represents the most important feature of the multistable mechanical metamaterials. We summarize main design strategies of multistable mechanical metamaterials, including those based on self-assembly scheme, snap-through instability, structured mechanism and geometrical frustration, with a focus on the number and controllability of accessible stable states. Then we concentrate on unusual mechanical properties of these multistable mechanical metamaterials, and present their applications in a wide range of areas, including tunable electromagnetic devices, actuators, robotics, and mechanical logic gates. Finally, we discuss remaining challenges and open opportunities of designs and applications of multistable mechanical metamaterials.