Timothy Morrissey1 Shane Mitchell1 Alexandra Jaros1 Eric Ambos2 Christoph Keplinger1

1, University of Colorado Boulder, Boulder, Colorado, United States
2, Stretch Sense Ltd, Portland, Oregon, United States

Nearly a century ago, Nikola Tesla proclaimed, “that when new types [of electrostatic generators] are developed and sufficiently improved a great future will be assured to them”. Yet today, almost every energy generation process, spanning from conventional coal and nuclear power plants to renewables such as wind and hydroelectric, rely on the electromagnetic generator. While the electromagnetic generator excels under optimized conditions, where a steady flow of fluid forces the generator to rotate rapidly, they are unable to harness new, extensive sources of energy, such as ocean waves. Conversely, the fundamental principles of electrostatic generators allow for exploration of a variety of alternative sources of mechanical energy.

Exploiting the high energy density of supercapacitors, we introduce a new variable capacitance energy generator that uses electric double layers (EDL). Using a model system of NaCl, water, and titanium we demonstrate that the capacitance of the EDL can be controlled by changing the contact area of the electrode and electrolyte interface, thereby enabling the conversion of mechanical to electrical energy. We explore the potential of this new technology, specifically for harvesting ocean wave energy, where the wave motion of a naturally occurring electrolyte directly couples to the energy harvester.