High-efficiency ballistic electrostatic generator using microdroplets

Yanbo Xie, Diederik Bos, Lennart de Vreede, Hans L. de Boer, Mark-Jan van der Meulen, Mark-Jan van der Meulen, Michel Versluis, A.J. Sprenkels, Albert van den Berg, Jan C.T. Eijkel

Research output: Contribution to journalArticleAcademicpeer-review

59 Citations (Scopus)
121 Downloads (Pure)


The strong demand for renewable energy promotes research on novel methods and technologies for energy conversion. Microfluidic systems for energy conversion by streaming current are less known to the public, and the relatively low efficiencies previously obtained seemed to limit the further applications of such systems. Here we report a microdroplet-based electrostatic generator operating by an acceleration-deceleration cycle ('ballistic' conversion), and show that this principle enables both high efficiency and compact simple design. Water is accelerated by pumping it through a micropore to form a microjet breaking up into fast-moving charged droplets. Droplet kinetic energy is converted to electrical energy when the charged droplets decelerate in the electrical field that forms between membrane and target. We demonstrate conversion efficiencies of up to 48%, a power density of 160kWm(-2) and both high- (20kV) and low- (500V) voltage operation. Besides offering striking new insights, the device potentially opens up new perspectives for low-cost and robust renewable energy conversion.
Original languageUndefined
Pages (from-to)3575
Number of pages5
JournalNature communications
Publication statusPublished - 7 Apr 2014


  • IR-90571
  • METIS-303713
  • EWI-24681

Cite this