The use of commercial atomic force microscopes (AFM) operating in the noncontact mode for surface force measurements is critically reviewed. Approach curves (i.e., vibration amplitude versus tip–surface distance) using standard microfabricated tips are discussed with respect to the basic theory of an equivalent harmonic oscillator. Different artifacts are addressed. In particular, we show theoretically and experimentally that the force exerted by the layer of air confined between the cantilever and the surface is a major contribution to the force on the cantilever. However, by carefully choosing the parameters (essentially the vibration amplitude) for the measurement of the approach curve, and by taking into account the damping within the confined air layer, we succeeded in measuring reliable surface force profiles with commercial AFM in the air and in describing them quantitatively by dispersion force interactions.

1.
G.
Binnig
,
C. F.
Quate
, and
C.
Gerber
,
Phys. Rev. Lett.
56
,
930
(
1986
).
2.
N. A.
Burnham
,
R. J.
Colton
, and
H. M.
Pollock
,
Nanotechnology
4
,
64
(
1993
).
3.
J. L.
Hutter
and
J.
Bechhoefer
,
J. Vac. Sci. Technol. B
12
,
2251
(
1994
).
4.
M.
Radmacher
,
M.
Fritz
,
J. P.
Cleveland
,
D. A.
Walters
, and
P. K.
Hansma
,
Langmuir
10
,
3809
(
1994
).
5.
C. D.
Frisbie
,
L. F.
Rozsnyai
,
A.
Noy
,
M. S.
Wrighton
, and
C. M.
Lieber
,
Science
265
,
2071
(
1994
).
6.
C.
Bustamante
and
D.
Keller
,
Phys. Today
48
,
32
(
1995
).
7.
R. M.
Overney
,
D. P.
Leta
,
C. F.
Pictroski
,
M. H.
Rafailovich
,
Y.
Liu
,
J.
Quinn
,
J.
Sokolov
,
A.
Eisenberg
, and
G.
Overney
,
Phys. Rev. Lett.
76
,
1272
(
1996
).
8.
R. G.
Winkler
,
J. P.
Spatz
,
S.
Sheiko
,
M.
Möller
,
P.
Reineker
, and
O.
Marti
,
Phys. Rev. B
54
,
8908
(
1996
).
9.
J. N. Isaraelachvili, Intermolecular and Surface Forces (Academic, London, 1985).
10.
Y.
Martin
,
C. C.
Williams
, and
H. K.
Wickramasinghe
,
J. Appl. Phys.
61
,
4723
(
1987
).
11.
G. Y.
Chen
,
R. J.
Warwick
,
T.
Thundat
,
D. P.
Allison
, and
A.
Huang
,
Rev. Sci. Instrum.
65
,
2532
(
1994
).
12.
W. A.
Ducker
,
R. F.
Cook
, and
D. R.
Clarke
,
J. Appl. Phys.
67
,
4045
(
1990
).
13.
W. A.
Ducker
and
R. F.
Cook
,
Appl. Phys. Lett.
56
,
2408
(
1990
).
14.
Park Scientific Instruments Data Sheets.
15.
M. Kirk (private communication).
16.
A. W. Adamson, Physical Chemistry of Surfaces (Wiley, New York, 1976).
17.
T. R.
Albrecht
,
P.
Grütter
,
D.
Horne
, and
D.
Rugar
,
J. Appl. Phys.
69
,
668
(
1991
).
18.
The vibration amplitude calibration is done by contacting the surface with the tip and measuring the evolution of the raw A–B signal (signal of the dual photodiode of the deflection detection system, proportional to the deflection of the cantilever) coming from the AFM head with the extension of the Z piezo. By measuring the vibration amplitude of the electrical signal raw A–B and multiplying by the conversion coefficient, we obtained the vibration amplitude of the cantilever.
19.
L. D. Landau and E. M. Lifschitz, Fluid Mechanics (Pergamon, London, 1959).
This content is only available via PDF.
You do not currently have access to this content.