Download Speaker: Dr

Speaker: Dr. Jason Cleveland
Title: Dual Frequency Atomic Force Microscopy
Abstract:
Scanning probe microscopy (SPM) uses a number of different scanning modes to
characterize surface topography and other characteristics. We will present a new SPM
imaging mode that goes beyond traditional phase image in measuring mechanical and
chemical properties. In this new imaging mode, Dual AC™, a cantilever is driven at
or near two of its flexural eigenmodes. For most cantilevers, these eigenmodes are
non-harmonic. The 2nd eigenmode amplitude and phase show strikingly different
contrast from the same fundamental eigenmode signals. As in traditional AC imaging,
the cantilever and imaging parameters can be chosen such that the tip-sample
interactions are either attractive or repulsive. In general, if the cantilever is
maintained in the attractive state, the 2nd eigenmode is sensitive to long ranged forces
and if the cantilevers is maintained in the repulsive state, the 2nd eigenmode is
sensitive to mechanical properties of the sample. Data on Magnetic and Electric Force
Microscopy (MFM and EFM) samples, collagen fibers, and λ-digest DNA be shown
to support this.
Note: Dr. Jason Cleveland is a co-founder of Asylum Research and is currently Chief
Executive Officer. Asylum Research a privately held company that is the premier
manufacturer of advanced AFMs/SPMs. Dr.Cleveland has over 17 years of AFM
experience specializing in the physics of AFM. He has over 30 published papers, and
is a co-inventor on six patents. Previously, he was a Research Scientist at Digital
Instruments (now Veeco). He received his PhD from the University of California
Santa Barbara and MS from University of Minnesota.