Miniaturized Power Supplies: Research on Micro-fluidic Rechargeable Batteries

With the fast growth in the Micro-Electromechanical System (MEMS) market, there is also growing need for miniaturized power sources. MEMS devices are beginning to make significant contributions in new subjects, including Lab-on-Chips (LOC) and other micro-fluidic devices, wireless communications, sensors, and optics. In all these technologies, electric power is a vital issue for the further development of the MEMS field. Large numbers of MEMS devices are still powered by external (macroscopic) power supplies, which in many cases lead to inter-connection problems, cross-talk, (electronic) noise, difficulties in controlling the power delivered, and most importantly, compromise the advantage of reduction in device size. In contrast, this complexity is reduced if miniaturized site-specific power is employed, and therefore improvements in noise and power efficiency may be achieved. Past investigations has been showed that the conflicting requirements which prevent good performance, high capacity, and long durability of rechargeable batteries can be (partly) eliminated when the cell is miniaturized and operated with a flowing electrolyte as a continuous electrochemical reactor. The proposed micro battery concept consists of one (or more) micro channel(s) which is (are) manufactured into a micro-fluidic/MEMS device which needs an on-board power source to fulfill its task.

The micro-fluidic batteries have great potential to be employed as the standard power source in MEMS and LOC devices. Also, it is attractive to number up these devices to obtain power systems for conversion and storage of larger amount of energy, e.g. combined with photovoltaic cells or wind turbines as an autonomous (remote) energy supply system. The potential of this project include sustainability and environmental considerations. Miniaturized rechargeable batteries decrease the need for raw material. The enhanced lifetime as well as the less waste generated by production, effects positively the entire cradle-to-grave cycle of small scale power sources.

The student  will be involved with the identification of the physical and chemical phenomena occuring in the micro-fluidic battery on the basis of a literature research. After the identification of the relevant phenomena, the governing equations for electrolyte flow, mass transfer of species, chemical reactions, and thermodynamics/heat transfer have to be identified.

The primary goal is to set-up a simple but effective 1-D model of the phenomena within the micro-fluidic battery. The model should reflect the essential physicochemical features with a low level-of-detail and should be solved with either MATLAB or a commercial CFD code.

Gita Kumari
Faculty Supervisor: 
Dr. Dominik P.J. Barz