Harvest of Motion

This article discusses that a small-scale generator uses a catch-and-release strategy that can turn a casual stroll into useful electric energy. Many devices now require fractions of a watt continuously, often with occasional bursts of 1 to 10 W during peak activity. However, batteries occupy device volume and have limited life. Even rechargeable batteries can withstand only a finite number of charge cycles and, perhaps most important, recharging them can be inconvenient or expensive. Engineers must develop strategies to harness the abundant energy in low-frequency, time-varying motion before energy harvesting can achieve its greatest potential. Water waves, swaying and bouncing structures, and biomechanics are potential environmental energy sources that are largely out of the reach of the current vibration-inspired, motion harvesting technologies. Being able to economically convert low-speed motion to electricity will be a key to realizing practical long-term power generation for distributed devices. The Veryst energy-harvesting concept is one approach that intends to do just that. As with other energy harvesting projects, much work remains, but initial research and development suggest strong potential.