Bubbler: A Novel Ultra-High Power Density Energy Harvesting Method Based on Reverse Electrowetting.

Tsung-Hsing Hsu,Tom Krupenkin,J Ashley Taylor,Supone Manakasettharn

doi:10.1038/srep16537

Abstract

We have proposed and successfully demonstrated a novel approach to direct conversion of mechanical energy into electrical energy using microfluidics. The method combines previously demonstrated reverse electrowetting on dielectric (REWOD) phenomenon with the fast self-oscillating process of bubble growth and collapse. Fast bubble dynamics, used in conjunction with REWOD, provides a possibility to increase the generated power density by over an order of magnitude, as compared to the REWOD alone. This energy conversion approach is particularly well suited for energy harvesting applications and can enable effective coupling to a broad array of mechanical systems including such ubiquitous but difficult to utilize low-frequency energy sources as human and machine motion. The method can be scaled from a single micro cell with 10−6 W output to power cell arrays with a total power output in excess of 10 W. This makes the fabrication of small light-weight energy harvesting devices capable of producing a wide range of power outputs feasible.

Highlights

Since late 1990 s portable electronic devices such as mobile phones, tablets, and laptops became an indispensable part of our daily life
Increasing the droplet oscillation frequency represents a effective way to raise the power density generated by the reverse electrowetting on dielectric (REWOD)
One possible way to circumvent this issue is to utilize the energy harvesting approach that does not rely on the mechanical energy source to generate the required high frequency excitations but, instead, utilizes an internal fast oscillation process, which is independent from the mechanical energy source behavior

Summary

Introduction

Since late 1990 s portable electronic devices such as mobile phones, tablets, and laptops became an indispensable part of our daily life. Typical examples of these sources include human and machine motion, waves and tides, wind and temperature induced motion of building or other large structures, etc All of those sources can generate high level of forces, and provide substantial mechanical power, but their characteristic frequency is too low to enable high energy harvesting power densities that the REWOD process is capable of achieving. One possible way to circumvent this issue is to utilize the energy harvesting approach that does not rely on the mechanical energy source to generate the required high frequency excitations but, instead, utilizes an internal fast oscillation process, which is independent from the mechanical energy source behavior The challenge with this approach is to find a practical method of achieving such fast internal oscillation dynamics without resorting to complex mechanical or hydraulic systems

Methods

Results

Conclusion