Electrothermal ac electro-osmosis Academic Article uri icon


  • Two ac polarization mechanisms, charge accumulation due to electrode double layer charging and bulk permittivity/conductivity gradients generated by Joule heating, are combined in the double layer by introducing zwitterions to produce a new ac electrokinetic pump with the largest velocity (>1 mm/s) and flow penetration depth (100 μm) reported for low-conductivity fluids. The large fluid velocity is due to a quartic scaling with respect to voltage, as is true of electrothermal flow, but exhibits a clear maximum at a frequency corresponding to the electrode double layer inverse RC time. © 2009 American Institute of Physics.

author list (cited authors)

  • Gagnon, Z. R., & Chang, H.

citation count

  • 22

publication date

  • January 2009