Energy Harvesting with a Liquid-Metal Microfluidic Influence Machine

TL;DR

This paper introduces a novel microfluidic energy harvesting device that converts mechanical flow energy into electricity using liquid metal droplets, with potential for high efficiency and scalability.

Contribution

It presents a new liquid-metal microfluidic influence machine design that achieves initial power output and suggests significant improvements through optimization.

Findings

Initial power output of 4 nW demonstrated

Potential to increase power by over 1000 times with optimization

Efficiency could exceed 90% with viscous dissipation limits

Abstract

We describe and demonstrate a new energy harvesting technology based on a microfluidic realization of a Wimshurst influence machine. The prototype device converts the mechanical energy of a pressure-driven flow into electrical energy, using a multiphase system composed of droplets of liquid mercury surrounded by insulating oil. Electrostatic induction between adjacent metal droplets drives charge through external electrode paths, resulting in continuous charge amplification and collection. We demonstrate a power output of 4 nW from the initial prototype and present calculations suggesting that straightforward device optimization could increase the power output by more than 3 orders of magnitude. At that level the power efficiency of this energy harvesting mechanism, limited by viscous dissipation, could exceed 90%. The microfluidic context enables straightforward scaling and parallelization, as well as hydraulic matching to a variety of ambient mechanical energy sources such as human locomotion.