Measurement of Disjoining Pressure of a Molecularly Thin Lubricant Film by Using a Microfabricated Groove

Abstract

A new method for measuring disjoining pressure of molecularly thin lubricant film with a microfabricated groove has been developed. The shape of the meniscus of a thin film in the groove was measured by atomic force microscopy, and the disjoining pressure was obtained from the Laplace pressure obtained from the curvature of the meniscus. The result obtained experimentally for a perfluoropolyether lubricant on a silicon surface agrees well with that predicted theoretically for an apolar polymer liquid. Moreover, we have demonstrated the intermolecular interaction between a thin film and a solid surface can be investigated by the method.