Single micro-channel formation in a gap between probe electrodes by freezing an aqueous electrolyte.

A size-tunable micro-channel is fabricated in a gap between two probe electrodes by freezing aqueous KCl. The channel has been characterized by resistance measurements and channel blocking by resistive particles. The channel size can be varied by the temperature even after the preparation of the channel. The channel is potentially useful not only for size-selective particle counting but also for the size-selective separation or filtration of particles and macromolecules.