Design and Fabrication of Addressable Microfluidic Energy Storage MEMS Device

• Published in: Journal of microelectromechanical systems 2012-12, Vol.21 (6), p.1392-1401
• Main Authors: Lifton, V. A., Simon, S., Holmqvist, J., Ebefors, T., Jansson, D., Svedin, N.
• Format: Article
• Language: English
• Subjects: Applied fluid mechanics; Applied sciences; Array; Batteries; Condensed matter: structure, mechanical and thermal properties; Electrodes; Electronics; electrowetting; Exact sciences and technology; Fluid dynamics; Fluidics; Fundamental areas of phenomenology (including applications); Glass; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; lithium; Llithium; Mechanical instruments, equipment and techniques; membrane; microelectromechanical systems (MEMS); microfluidic; Microfluidics; Micromechanical devices and systems; Miscellaneous; Physics; reserve battery; Silicon; Solid-fluid interfaces; Storage and reproduction of information; superhydrophobic; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Wetting
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2012.2208218

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 2 and Li/CF x ) have been used as anode and cathode in the battery with LiClO 4 -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.