Elastic instabilities of a ferroelastomer beam for soft reconfigurable electronics

We examine the flexural deformation and snap-through instability of a pre-buckled ferroelastomer beam. The beam is composed of ferromagnetic and electrically conductive microparticles suspended in a polydimethylsiloxane (PDMS) matrix. Bending and snap-through are controlled remotely with an external magnetic field. The observed magneto-flexural coupling is in reasonable agreement with predictions from an analytic model based on elastic rod theory and variational techniques. Moreover, such coupling results in stable and unstable bending modes that can be exploited for a soft-matter, field-controlled, reconfigurable electrical relay. These two flexural modes correspond to (i) low-power binary (stable) switching and (ii) a more rapid >10Hz response that is achieved by momentarily driving the beam to a slightly deformed configuration. This combination of stable and unstable switching states provides a new approach for harnessing elastic instabilities and a means to create a low power, yet rapidly responsive switch for soft electronic systems.