This Sensors and Sensor Networks (Sensors) Individual Investigator (SII) grant will fund the development of advanced 3D microbatteries and smart battery arrays for miniature sensors. The work involves the manufacture of microbatteries based on 3D carbon electrode arrays fabricated by the pyrolysis of photo-lithographically patterned photoresist. The use of 3D carbon electrode arrays enhances the surface to volume ratio of the microbattery, resulting in increased reaction surface area and decreased ion diffusion distances. With each electrode composed of thousands of electrode elements, pairs of such electrodes will be fabricated in a novel type of switchable array of microbatteries so that different voltages and currents can be continuously accessed depending on the need of the application at hand. Completed C-MEMS Li-ion rechargeable microbatteries are expected to feature superior energy densities and very fast charge/discharge characteristics compared to current 2D batteries. The work entails the following major tasks: optimization of the microbattery design through modeling and electrochemical experimentation with arrays of differently shaped and differently arranged C-MEMS posts, design and implementation of switching patterns, optimization of C-MEMS materials properties such as surface roughness and porosity, improvement of Li-ion charging/discharging characteristics of the negative electrodes (including the use of doping of the carbon electrodes), and the fabrication of positive electrode posts and an electrolyte.
If successful, the new material and manufacturing approach for batteries developed here can also be used for novel miniaturized electrochemical sensors, super capacitors and fuel cells. The new advanced batteries could be integrated into remote sensor networks, optoelectronics and implantable biomedical devices. The work will foster interdisciplinary interactions with postdocs and students at all levels and from various backgrounds including mechanical engineering, electrical engineering, chemistry and materials science. The information and results of this project will be broadly disseminated to enhance scientific and technological understanding through presentation at scientific conferences and publication in scientific journals. This research project should effect graduate and undergraduate education in MEMS and nanotechnology but also will try to raise the awareness in MEMS and NEMS for high school students in the local area (UCI has a summer program set-up just for this).
