We present experimental evidence of self-healing shear cracks at a gel/glass interface. This system exhibits two dynamical regimes depending on the driving velocity: steady sliding at high velocity $(>V_{\mathrm{c}}\simeq 100–125\mu \mathrm{m}/\mathrm{s})$, characterized by a shear-thinning rheology, and periodic stick-slip dynamics at low velocity. In this last regime, slip occurs by propagation of pulses that restick via a “healing instability” occurring when the local sliding velocity reaches the macroscopic transition velocity $V_{\mathrm{c}}$. At driving velocities close below $V_{\mathrm{c}}$, the system exhibits complex spatiotemporal behavior.

• Received 18 October 2001

DOI:https://doi.org/10.1103/PhysRevLett.88.075509