Tuneable hydrophoretic separation using elastic deformation of poly(dimethylsiloxane)

This paper demonstrates a method for tuning elastomeric microchannels for hydrophoretic separation made in poly(dimethylsiloxane) (PDMS). Uniform compressive strain is imposed on the elastomeric microchannel between two acrylic substrates by fastening the bolts. The elastomeric microchannel can change its cross-section during compression, simultaneously tuning the criterion for hydrophoretic ordering. The change of the channel cross-section under compression is studied using a confocal microscope and finite element method (FEM). By pressing the channel for hydrophoretic separation, we achieved tuning of the separation criterion from 7 to 2.5 mu m in particle diameter.