Kirigami Actuators*

Inspired by the Japanese art of kirigami, we introduce new ways of modify thin sheets of material to craft dynamical assembling of complex shapes for mechanical actuation. We exploit the fundamental principles of this art through careful tuning of the geometry and topology of these cuts on thin sheets and propose the design of actuators that scale from macroscopic sheets of mylar to atomically thin 2D materials (graphene and MoS₂). By understanding the mechanics of a single cut on a sheet, we can take advantage of the nonlinear and anisotropic responses to external forces to generate four fundamental modes of linear actuation: roll, pitch, yaw, and lift, essentially creating a new class of mechanical metamaterials. Our model shows that the dependence of the sheet deflections on sheet thickness is of a higher order, thus providing an explanation for the observed invariance in kirigami actuator behaviors from the macroscale to the nanoscale.