title: New surface forces apparatus using two-beam interferometry.
abstract: We designed a new surface forces apparatus for measuring the interactions between two nontransparent substrates and/or in nontransparent liquids. The small displacement of a surface, the bottom one in this study, was measured by the two-beam (twin path) interferometry technique using the phase difference between the laser light reflected by the fixed mirror and that by the mirror on the back of the bottom surface unit. It is possible to determine the distance with a resolution of 1 nm in the working range of 5 microm. This apparatus was successfully applied to measure the forces between mica surfaces in pure water and aqueous KBr solutions.
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakuma
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizukami
authors.forename: Takashi
authors.initials: T
authors.lastname: Abe
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fukao
authors.forename: Haruo
authors.initials: H
authors.lastname: Tajima
authors.forename: Kazue
authors.initials: K
authors.lastname: Kurihara