Impulsive Elastic Energy Release from a Resilin-like Elastomer

Small organisms and micro-robotic devices can use elastically-driven motion to achieve astonishing accelerations. To understand the size-scaling limits of elastic performance, we measured the elastic recoil of elastomer bands with mechanical properties similar to the biological protein resilin. By tracking the center-of-mass motion of elastomer bands using high-speed videography, three metrics of kinematic performance were quantified: the maximum velocity, peak acceleration, and duration of energy release. The velocity of the elastomer bands was found to be size-scale independent, while smaller bands demonstrated larger accelerations and shorter durations of elastic energy release. The scaling equations derived from these measurements are consistent with the performance of small organisms which utilize elastically-driven motion. Engineered micro-robotic devices found in the literature do not follow the same size-scaling relationships, which suggests an opportunity for improved design of engineered devices. The scaling relationships we extract for each metric of kinematic performance (velocity, acceleration, duration) determine principles of materials selection for use in elastically-driven motion.