Bacterial cell manipulation by dielectrophoresis on a hydrophobic guide structure

We present a simple bacterial cell manipulation method based on dielectrophoresis (DEP) and droplet evaporation control using micro-patterned electrodes of the DEP effective area and a hydrophobic guide structure. Polystyrene particles were focused into intended areas by controlling the meniscus of evaporating droplets on the hydrophobic surface. Bacterial cells were efficiently assembled on an electrode array using DEP assisted by a hydrophobic guide structure. Simulations of an electric field and an electric field gradient that was dependent on the electrode shape confirmed that the design of an optimal electrode shape is important for increasing the DEP force for effective cell manipulation.

Graphical abstractWe present a simple bacterial cell manipulation method based on dielectrophoresis (DEP) and evaporation control using micro-patterned electrodes of the DEP effective area and a hydrophobic guide structure. Droplet evaporation mechanism on the hydrophobic surface helped to focus particles into the rectangular DEP effective area. Our hydrophobic guide structure used the hydrophobic and the hydrophilic evaporation mechanisms together to focus particles in the droplet.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► Hydrophobic guide structure with hydrophilic and hydrophobic region. ► Bacterial cells focused on the DEP effective electrode by the hydrophobic guide. ► Bacterial cells can be readily manipulated by DEP and droplet evaporation control.