Design and Fabrication of Addressable Microfluidic Energy Storage MEMS Device

Abstract

Design and fabrication of microfluidic energy storage devices that are based on the control of the liquid electrolyte inside a power cell are presented. A 12-cell array of individually addressable reserve microbatteries has been built and tested, yielding ~ 10-mAh capacity per each cell in the array. Lithium and manganese dioxide or carbon monofluoride (Li/MnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and Li/CF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> ) have been used as anode and cathode in the battery with LiClO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> -based electrolyte. Inherent power management capabilities allow for sequential single cell activation based on the external electronic trigger. The design is based on the superlyophobic porous membrane that keeps liquid electrolyte away from the solid electrode materials. When power is needed, battery activation (a single cell or several cells at once) is accomplished via electrowetting trigger that promotes electrolyte permeation through the porous membrane and wetting of the electrode stack, which combines the chemistry together to release stored electrochemical energy. The membrane and associated package elements are prepared using microelectromechanical system fabrication methods that are described in details along with the assembly methods.