title: In-plane contributions to phase contrast in intermittent contact atomic force microscopy.
abstract: Contrast in the phase response of intermittent-contact atomic force microscopy (IC-AFM) reveals in-plane structural and mechanical properties of polymer monolayers. This result is unexpected, as IC-AFM has previously only been considered as a probe of out-of-plane properties. Until now, AFM measurements of nanoscale in-plane properties have employed contact mode techniques. In-plane property measurements are possible with intermittent contact AFM because there is a small but significant component of tip motion parallel to the sample surface. This in-plane component of tip displacement is virtually universal in AFM, implying that oscillating-tip techniques generally are sensitive to in-plane material properties. We present a simple Hertzian model of intermittent-contact AFM that includes such an in-plane displacement.
authors.affiliation: Physics Department, University of Wisconsin-Madison, Madison, WI, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Marcus
authors.forename: M A
authors.initials: MA
authors.lastname: Eriksson
authors.forename: Darryl Y
authors.initials: DY
authors.lastname: Sasaki
authors.forename: Robert W
authors.initials: RW
authors.lastname: Carpick