Manipulation of bacteria using three dimensional insulator based dielectrophoresis

Abstract

Insulator-based dielectrophoresis (iDEP) is a very promising technique for sorting microparticles based on their electrical properties. By using constrictions in a microchannel to generate large electric field gradients, the need for microfabricated electrode arrays is eliminated. In this work, three-dimensional insulator-based dielectrophoresis (3DiDEP) devices are fabricated using a novel micromachining technique. These devices are predicted and observed to exhibit higher trapping sensitivity than existing devices in the literature; this allows for efficient trapping of microparticles and bacteria at low applied fields with minimal thermal shock on the particles due to Joule heating effects. The dielectric properties of a range of bacteria, as well as polystyrene beads are examined. The impact of these results on the development of microbial fuel cells and portable low-cost clinical diagnostic tools is also discussed.