Single-Pore Membranes Gated by Microelectromagnetic Traps

Gating of a single pore with a microelectromagnetic trap consisting of a single-turn gold wire microfabricated on a silicon membrane is described. A single micrometer-sized pore in the center of the microcoil conducts ionic current under the application of an applied transmembrane potential. When energized, the microelectromagnetic trap attracts a droplet of magnetic fluid, bringing the fluid to rest in the center of the trap, blocking the transport of ions through the pore, turning it off. Reversal of the current flow through the trap moves the droplet to the periphery of the trap, turning the pore on.