抄録
We have investigated the elongational motion of magnetic gels under gradient magnetic fields. The magnetic gel was made from fine particles of iron oxide and a network of poly(vinyl alcohol) crosslinked by glutaraldehyde. The elongation increased with increasing the magnetic field strength up to 1200 mT. The elongation increased as increasing the concentration of magnetic particles; oppositely, it decreased as increasing the crosslinking density. It was found that the elongation can be explained by a classical theory of magnetism that the elongation is proportional to the product of magnetization and the field gradient. The effect of load on the elongation has been also investigated. The coefficient of the conversion from magnetic energy to mechanical one was estimated to be 10-4 %, which is nearly independent of the load.
