Energy Harvesting with a Liquid-Metal Microfluidic Influence Machine

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.

High Voltage Generation by Fiber-Coupled Pulsed Laser for a Simple Receiver Circuit Structure

“…This largely owes to the advances in the field of micro-electromechanical systems (MEMS) and the microfluidics technology, combined with the interest in developing a miniature energy harvesting generator to power small portable devices. Recent works based on microfluidics technology include a chip-based Kelvin dropper [24], a ballistic Kelvin dropper [25], and a mercurydroplet-based influence machine [26]. Recent works based on MEMS technology include a varying capacitance machine [27], [28] and an influence machine [29],…”

Local Order in Liquid Gallium–Indium Alloys

“…Room-temperature liquid alloys, also known as liquid metals, typically have liquidus temperatures below 300 °C and are based on the low-melting elements gallium, bismuth, indium, cesium, sodium, and mercury as majority components . More recently, liquid metals were discovered as heterogeneous catalysts with the renewable surface for CO 2 reduction , or petrol refining, templates for synthesis of 2D-materials, for tailored growth of microcrystals and as electrode material in all-liquid batteries. , In particular, gallium alloys display low-melting points, wide liquid range, low toxicity, and chemical inertness making them suitable as liquid-metal inks for flexible printed electronics , or as pumps and actuators in microfluidic devices. − A suspension of magnetic particles in liquid gallium can function as a shape-shifting miniature machine with field-assisted solid–liquid transition …”

Robust Impact Effect and Super-Lyophobic Reduced Galinstan on Polymers Applied for Energy Harvester

“…According to Krupenkin et al, electrical power was generated by squeezing the liquid droplets between vibrating plates based on the reverse electrowetting principle [9]. Moon et al found that electrical energy generation is achieved by mechanically modulating the water droplet without an external bias voltage source [10][11][12][13][14]. The water-TENG (triboelectric nano generator) was intensively studied due to its great potential for harvesting the energy from water triboelectrification [15][16][17][18][19][20][21][22][23][24][25].…”

“…Mercury is the most well-known liquid metal, which can replace ionic liquid and water in a microfluidic energy harvester. Yang et al proposed an energy harvester using mercury droplets and ionic liquid marbles rolling across a charged electret film [13,26,27]. Nevertheless, its toxicity and higher vapor pressure pose a challenge for its widespread applications.…”