Microfabricated secondary batteries for remote, autonomous, electronic devices

Lacking from much of MEMS technology is a viable strategy for supplying power. In particular, MEMS intended to be autonomous require microscopic energy storage. The purpose of this paper is to discuss the design of microscopic batteries to fill this need. Energy storage strategies for MEMS, and design considerations for batteries, are reviewed. The experimental results of initial microscopic battery demonstration is also presented. A range of secondary battery chemistries were demonstrated in miniature or microscopic prototype cells, with both solid and liquid electrolytes. Their various attributes and performances were assessed, and two different chemistries were selected for initial development, Ni/Zn and Li/ion. Successful versions of the sealed Ni/Zn and unsealed Li-ion cells have been demonstrated. The batteries are fabricated using existing MEMS fabrication procedures, so that complete integration is possible. These batteries offer far more energy storage capability than a capacitor, sufficient to operate many MEMS devices for extended time periods without a significant recharge. Autonomous and remote MEMS devices thus become feasible. The use of integrable microscopic batteries in MEMS represents a significant enablement of MEMS technology.