When it comes to things that are ultrafast and lightweight, robots can't hold a candle to the fastest-jumping insects and other small-but-powerful creatures. New research published in the journal Science could help explain why nature still beats robots--and describes how machines might take the lead. The multi-institutional team of authors includes Associate Professor Sarah Bergbreiter, who studies microrobotics at the University of Maryland's A. James Clark School of Engineering. Take the smashing mantis shrimp, a small crustacean not much bigger than a thumb. Its hammer-like mouthparts can repeatedly deliver 69-mile-per-hour wallops more than 100 times faster than the blink of an eye to break open hard snail shells.

Mechanical power limitations emerge from the physical trade-off between force and velocity. Many biological systems incorporate power-enhancing mechanisms enabling extraordinary accelerations at small sizes. We establish how power enhancement emerges through the dynamic coupling of motors, springs, and latches and reveal how each displays its own force-velocity behavior. We mathematically demonstrate a tunable performance space for spring-actuated movement that is applicable to biological and synthetic systems. Incorporating nonideal spring behavior and parameterizing latch dynamics allows the identification of critical transitions in mass and trade-offs in spring scaling, both of which offer explanations for long-observed scaling patterns in biological systems.