Developments for a Fluid Valve Using Magnetic Gels

We have fabricated the fluid valve in a fluid tube of 800 micro m in diameter using magnetic gels. The magnetic gel was made from a network of poly(vinyl alcohol) crosslinked by glutaraldehyde and fine particles of iron oxide. When a weak magnetic field was applied to the valve, the valve came into a microtube and, as a result, a flow of water stopped. The valve opened and closed in response to the magnetic field generated by a permanent magnet. The valve worked well under the pressures of water from 0.3 MPa to 1.6 MPa.