Experimental realization of critical thermal fuse rupture

We present an experimental realization with electrical composites of the thermal fuse model [D. Sornette and C. Vanneste, Phys. Rev. Lett. 68, 612 (1992)], proposed as a paradigm of dynamical rupture in heterogeneous media. An isolating polymer matrix is filled with conducting particles, and the particle-particle contacts evolve due to thermal expansion of the matrix as a function of the applied current I. Above a critical current, the electric resistance R increases as a power law of time to rupture R similar to (t(r) - t)(-alpha), with alpha similar or equal to 0.65, and the breakdown time t(r) scales as t(r) similar to I-2 in agreement with the model.