Thermoresistance and Giant Magnetoresistance of Magnetorheological Elastomers

A new magnetorheological elastomer composite (MRE) was developed with a resistance which is strongly sensitive both to temperature and pressure. The electrical resistance of this MRE was investigated versus pressure and temperature. The resistance of the composite was recorded versus pressure for seven different values of the temperature. The mechanism of electrical conduction was modeled and assessed experimentally. An other type of composite, prepared with a softer elastomer, showed a giant magnetoresistance with a decrease by 3 orders of magnitudes for a field of only 100kA/m (1250Oe); It was shown that the magnetic pressure acted like mechanical pressure for field lower than 100 kA/m but beyond the magnetoresistance was saturating contrary to piezoresistance.