FORCE-SENSITIVE RESISTOR OF CARBON-FILLED LIQUID SILICONE-RUBBER

The effects of carbon content, tensile force, and temperature on the e lectrical resistance of carbon-filled liquid silicone rubber composite s are studied. The relaxation process of resistance following loading can be described by an exponential function. The force dependence of t he equilibrium resistance can be expressed by a second order polynomia l, and such a relationship can be derived from the quantum mechanical tunneling conduction mechanism by assuming that the separation distanc e between carbon aggregates changes as a function of the tensile force with a form of Delta w = kF(2). Combining with the experimental data and typical values of theoretical parameters, the elastic modulus, the separation distance, and the proportional constant k can be obtained. Finally, the temperature dependence of resistance can be interpreted by the general form of R=R(0)exp(const./T) with two different constant s at different temperature ranges. (C) 1996 American Institute of Phys ics.