Method and Apparatus For Mechanical Energy Harvesting Using Planar Microfluidic Device

A system for converting mechanical energy into electrical energy, the system including a plurality of separate planar components for performing the energy conversion, the plurality of separate planar components vertically stacked to minimize surface area coverage, wherein each separate planar component comprises

• a plurality of electrically conductive liquid droplets disposed in a planar arrangement;
• a planar electrode disposed in a parallel, spaced-apart relationship with the plurality of electrically conductive liquid droplets;
• a dielectric layer positioned between the plurality of electrically conductive liquid droplets and the planar electrode so as to form a capacitive structure therewith;
• an elastic spacer element disposed between the plurality of electrically conductive liquid droplets and the planar electrode so as to surround said plurality of electrically conductive liquid droplets, such that the application of mechanical energy to the apparatus compresses the elastic spacer element and the plurality of electrically conductive liquid droplets, increasing a contact area between said plurality of electrically conductive liquid droplets and the dielectric layer and also an overlap area with the planar electrode, increasing the capacitance value of the planar component;
• and
• an electrical circuit means, electrically coupled between the plurality of electrically conductive liquid droplets and the planar electrode so as to apply a bias voltage therebetween and transfer electrical current generated in response to the change in capacitance associated with the change in overlap area to a power consuming element,
• the current outputs from the separate planar components thereafter combined to provide the electrical energy output.

A method of converting mechanical energy into electrical energy comprising the steps of:

• disposing a plurality of electrically conductive liquid droplets on a substrate;
• covering the plurality of electrically conductive liquid droplets with a layer of dielectric material;
• surrounding the combination of the electrically conductive liquid droplets and layer of dielectric material with an elastic spacer element;
• positioning a planar electrode over the dielectric material so as to form a capacitive structure with the dielectric material and the plurality of electrically conductive liquid droplets;
• applying a predetermined bias voltage between the planar electrode and the plurality of electrically conductive liquid droplets;
• and
• subjecting the arrangement to a periodic mechanical force so as to compress and then decompress the elastic spacer and the plurality of electrically conductive liquid droplets in a manner to periodically change the capacitive value of the arrangement and create an electrical current output therefrom.