This Ph.D. project is aimed at the development of methods and devices to produce electrochemical energy from streaming water. A streaming potential and a streaming current are generated when liquid water is pumped through a porous medium.
During the initial stages of this project we have invented a novel way of energy conversion that we termed ‘ballistic energy conversion’ and with it have obtained a conversion efficiency of almost 50% [Xie et al., high efficiency ballistic electrostatic generator using microdroplets, Nature Communications 5 (2014) 3575; see also Xie et al., Lab Chip 14 (2014) 4171]. Furthermore we have shown increased efficiencies using injected gas bubbles and dissolved polymers [Nguyen et al., Highly enhanced energy conversion from the streaming current by polymer addition, Lab Chip 13 (2013) 3210; Xie et al.Strong enhancement of streaming current power by application of two-phase flow, Lab Chip 11 (2011) 4006].
At present the research in this project has entered a new phase in which we investigate two different platforms: the use of a centrifugal platform to launch charged water droplets for ballistic energy conversion, and the use of pressure-driven flow through highly charged membranes.