Bioinspired Soft Metamaterials for Soft Robotic Applications

In the field of soft robotics, the nonlinearities and large deformations typical of elastomeric materials are used to emulate complex phenomena typical of the animal kingdom. Introducing metamaterials further expands the design space of soft robotics, unlocking interesting and useful mechanical properties and granting novel functionalities to components. Here, we study a soft metamaterial that undergoes a global pattern reconfiguration due to buckling instability upon inflation. Studies thus far have induced global buckling instability through uniaxial compression or negative pressure, but we will introduce and leverage, for the first time, a global buckling instability due to positive pressure in a porous metamaterial. Both numerical and experimental approaches will be used to obtain pressure-volume curves and to characterize the buckling modes based on the geometrical properties of the 3D porous metamaterial. We will show how the buckling-induced reconfigurable and reversible behavior can be harnessed for gripping and sequential actuation purposes. Leveraging this instability as a means for actuation, we explore a new class of programmable soft actuators with distributed gripping and embedded sequencing capabilities.