Soft adhesive latches to control the kinematic response of a recoiling band*

Mantis shrimp, salamanders, and chameleons are just a few of nature’s overachievers relying on latch-mediated spring-actuation (LaMSA) to produce ultra-fast, powerful movements. Though latches are fundamental to LaMSA, the study of latch control is currently in its infancy and warrants further understanding to engineer LaMSA systems. We examine the impact of materials properties on the performance of contact adhesive latches. We conduct high-speed adhesion tests measuring the force and contact area as a probe-tipped polyurethane band is stretched to make contact with the adhesive latch. Altering the band strain input allows us to control the deformation mode observed during high-speed imaging of interface separation. Energy not dissipated by the adhesive latch is converted into kinetic energy of the recoiling band. By tuning the adhesive properties of the latch, we can control the maximum velocity (23 ms^-1) and acceleration (6.2 x 10³ ms^-2) of the recoiling band. The insights gained from this work will provide a better understanding of how LaMSA systems rely on latches to store and mediate energy to achieve small, power-amplified movements.