ABSTRACT
Electrical currents produced when a pressure sensitive adhesive is peeled from a copper substrate provide a sensitive probe of the dynamics of interfacial failure. This current is produced when charged adhesive pulls away from the metal. Time-series analysis of the current fluctuations shows that the peel dynamics displays fractal behavior, with a correlation dimension of about 2.3. The small size of this dimension suggests that the dynamical behavior of the peel front could be described with a relatively simple model (3–5 degrees of freedom). Estimates of the Lyapunov exponent, λ, indicate a large, positive exponent (≈ 100 bits/s), showing that fluctuations along the peel front become inherently unpredictable on time scales of tens of ms (λ −1). The presence of a positive Lyapunov exponent demonstrates conclusively that the current fluctuations (and thus adhesive detachment) exhibit deterministic chaos.
