Stiction, adhesion energy, and the Casimir effect in micromechanical systems

We measure the adhesion energy of gold using a micromachined cantilever beam. Stress and stiffness of the beam are characterized by measuring the spectrum of mechanical vibrations and the deflection due to external force. We induce stiction between the beam and a nearby surface, employing capillary forces to determine the adhesion energy γ. The obtained value γ=0.06 J/m^2 is a factor of 6 smaller than that predicted by idealized theory. This discrepancy may arise from surface roughness or an adsorbed layer intervening between the contacting surfaces in these mesoscopic structures.