THE DEPARTMENT OF AT STATE
UNIVERSITY OF NEW YORK, POTSDAM N.Y. CHEMISTRY 

Research with
Students Learning through research Raman Imaging and Spectroscopy Lab Chemical and Biological Applications of Raman Spectroscopy (pdf, 7 MB)
Quartz Crystal Nanobalance Lab Studies
Electrochemical Quartz Crystal Nanobalance (EQCN) technique utilizes quartz vibrations and piezoelectric effect to measure mass changes as small as a fraction of a monolayer of atoms
Back to 
Professor Maria Hepel hepelmr@potsdam.edu Atomic Force Microscopy Laboratory 
Stowell Hall 44 Pierrepont Ave. Potsdam , NY 13676, U.S.A. Tel.: +1.315.267.2267 Fax: +1.315.267.3170 

AFM Fundamentals
AFM tip interaction with sample (Veeco Nanoscope IIIa)
Force versus distance curve
Atomic Force Measurements
The action at the AFM tip can
be viewed as two components:
 a sensor that responds to a
force
 a detector that measures the
sensor response
Hooks law:
F = kz where F is the force
k is the spring
constant of a cantilever and
z
is the vertical cantilever displacement.
The spring constant of a
cantilever can be expressed as:
k = Et^{3}w/4L^{3} where E is the elasticity modulus, which is a measure of
the restoring
force upon extention,
t is the
thickness of the cantilever.
In general, t is difficult to
measure, however, it can be determined from the resonance frequency
fr:
F_{r} = 0.162 (E/d)^{1/2}t/L^{2} where d is the density of the cantilever material.
The values of k
are in the range from 0.01 to 50 N/m and are specified by the cantilever
manufacturer.

AFM Tip
Sharpened AFM Tip End
Nanowires assembled from MoO_{3 Semiconductor Metal Oxide}
AFM Image of a Monolayer Film of Bovine Serum Albumin on gold EQCN electrode, film thichness: 38 nm
The AFM/STM instrumentation has been funded by the NSF CCLI program, Award No. 0126402. 