Characterizing electrokinetic mobility of microparticles using in-line holographic microscopy


  • Mikko Haapalainen
  • Ville Kaikkonen
  • Ismo Kinnunen
  • Anssi Mäkynen



Traditionally, electrokinetic phenomena are demonstrated under a microscope. Since an ordinary light microscope has a short depth of focus and in many cases the electrokinetic phenomenon may take place in a relatively large volume, it is essential to use a microscopic method which has a long depth of focus and adequate depth resolution. The advantage of using a transparent platform and in-line holographic imaging for particle tracking is shown. Dielectrophoretic (DEP) particle motion is demonstrated on a fully transparent platform with 2D indium-tin-oxide (ITO) electrodes, and images of the whole sample volume are reconstructed using the digital in-line holographic method (DIHM) in order to find the 3D positions and speeds of the particles influenced by the DEP force and other electrokinetic forces. DIHM imaging proved to be a practical tool for analyzing particle motion due to multiple, simultaneously acting, electrokinetic forces.

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How to Cite

M. Haapalainen, V. Kaikkonen, I. Kinnunen, and A. Mäkynen, “Characterizing electrokinetic mobility of microparticles using in-line holographic microscopy”, Photonics Lett. Pol., vol. 3, no. 2, pp. pp. 85–87, Jun. 2011.