A DC/DC booster circuit was fabricated and tested for use with microbial fuel cells (MFCs) to increase the typical operational voltage (100-300 mV) to a maximum power of >3V. In steady state, the low power DC/DC voltage booster circuit was sustainable, i.e., powered by the MFCs alone, but required an external power source to start (but not needed to maintain) the oscillator. The operating principle and function of each part of the circuit is described. A procedure for determining the optimal set of values for each component in the circuit was established. The performance of the circuit was demonstrated using three Shewanella oneidensis MR-1 based MFCs connected in parallel. The power consumption of the booster circuit was less than 20 mu W, which was less than the output from the three MFCs. After the output capacitor was charged to 5 V. the booster circuit can be powered by the MFCs alone. Under normal operation, the MFCs were able to power the booster circuit and a light emitting diode. (C) 2011 Published by Elsevier Ltd.