Microfluidics and Nanofluidics

, Volume 1, Issue 2, pp 161–167

Particle detection by electrical impedance spectroscopy with asymmetric-polarization AC electroosmotic trapping

Research Paper

DOI: 10.1007/s10404-004-0024-5

Cite this article as:
Wu, J., Ben, Y. & Chang, HC. Microfluid Nanofluid (2005) 1: 161. doi:10.1007/s10404-004-0024-5


Recently, considerable interest and effort have been devoted to the on-site detection of low-concentration pathogenic bacteria in order to deter infectious diseases and bioterrorism. Conventionally, bacteria detection involves culturing, which is time-consuming and unfeasible under field conditions. Microfluidic devices with integrated electrical detection will enable fast, low-cost, and portable sensing and processing of biological and chemical samples. AC electroosmosis (EO) is well-suited for integration into microsystems due to its low-voltage operation and no-moving-part implementation and microelectrical impedance spectroscopy can be integrated with AC EO for particle manipulation, leading to enhanced sensitivity due to a reduction of the transport time to the detector. Experiments are performed to find optimal conditions for obtaining particle and bacterial assembly lines on electrodes by AC EO and preliminary results show good resolution at a concentration of 104 bacteria/ml, indicating that combining AC EO with impedance measurement can improve the sensitivity of particle electrical detection.


AC electroosmosisBacteria detectionBiosensing electrokineticsMicroimpedance sensor

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Center for Micro-fluidics and Medical Diagnostics, Department of Chemical and Biomolecular EngineeringUniversity of Notre DameNotre DameUSA
  2. 2.Department of Electrical & Computer EngineeringThe University of TennesseeKnoxvilleUSA