A planar polymer microfluidic electrocapture device for bead immobilization

A planar microfluidic electrocapture device that captures and concentrates beads by a local electrical field has been assembled and tested. The device presented also enables on-line observations of electrically manipulated beads in a micro-channel. The design is based on a sandwich construction from a glass substrate and a PMMA-lid, using a patterned polyimide spacer to form the channel. Capture and release of 2 mu m polystyrene beads have been performed successfully at an applied potential of 300 V in 25 min. The captured sample plug and its parabolic shape is studied and discussed. The planar capture device design opens for using the electrocapture principle in future microfluidic tools, e. g. a fluidic switch.