Passive fuel delivery based on hydrophobic porous silicon for micro direct methanol fuel cells

This paper presents a novel micro direct methanol fuel cell (μDMFC) integrated with passive fuel delivery based on a surface tension driving mechanism to achieve power-free fuel supply. Unidirectional methanol-to-water smooth flow is achieved through the hydrophobic capillaries of the porous silicon membrane utilizing the liquid surface tension difference between methanol and water. The prototype is demonstrated to exhibit good fuel utilization and to operate for longer time compared with conventional μDMFCs. As such, it is believed to be more applicable for future μDMFCs.