| 43172 |
Creator |
c3baa1aae2495d9fcf383c433b46bfe0 |
| 43172 |
Creator |
ext-73ae06dc89c05e28315bf4e2f21ff792 |
| 43172 |
Date |
2012-11-16 |
| 43172 |
Is Part Of |
repository |
| 43172 |
Is Part Of |
p15205827 |
| 43172 |
abstract |
The measurement of the physical properties of surfaces on the nanoscale is a long-standing
problem, and the atomic force microscope (AFM) has enabled the investigation of surface
energies and mechanical properties over a range of length scales. The ability to measure
these properties for softer materials presents a challenge when interpreting data
obtained from such measurements, in particular because of the dynamics of the compliant
AFM microcantilever. This work attempts to better understand the interaction between
an AFM tip and samples of varying elastic modulus, in the presence of attractive van
der Waals forces. A theoretical model is presented in which the dynamics of the approach
of an atomic force microscope cantilever tip toward a surface, prior to and during
the van der Waals-induced jump-to phenomenon, are included. The cantilever mechanics
incorporates the motion of the air through which the cantilever moves, the acceleration,
inertia, and torque of the cantilever, and the squeezing of the fluid between the
cantilever tip and the surface, leading to elastohydrodynamic lubrication and deformation
of the substrate. Simulations of the cantilever approach are compared to measurements
performed using an atomic force microscope, and the effect of cantilever drive velocity
is investigated. Cantilevers presenting (1) spherical colloid probe tips and (2) pyramidal
tips are employed, and substrates exhibiting Young’s moduli of 3 MPa, 500 MPa, and
75 GPa are measured. The analysis presented could be extended to enhance understanding
of dynamic phenomena in micro/nanoelectromechanical systems such as resonators and
microrheometers, particularly those which contain soft materials and also where surface
interactions are important. |
| 43172 |
authorList |
authors |
| 43172 |
issue |
50 |
| 43172 |
status |
peerReviewed |
| 43172 |
uri |
http://data.open.ac.uk/oro/document/335228 |
| 43172 |
uri |
http://data.open.ac.uk/oro/document/335229 |
| 43172 |
uri |
http://data.open.ac.uk/oro/document/335230 |
| 43172 |
uri |
http://data.open.ac.uk/oro/document/335231 |
| 43172 |
uri |
http://data.open.ac.uk/oro/document/335232 |
| 43172 |
uri |
http://data.open.ac.uk/oro/document/335233 |
| 43172 |
uri |
http://data.open.ac.uk/oro/document/335328 |
| 43172 |
volume |
28 |
| 43172 |
type |
AcademicArticle |
| 43172 |
type |
Article |
| 43172 |
label |
Bowen, James and Cheneler, David (2012). A dynamic model of the jump-to phenomenon
during AFM analysis. Langmuir, 28(50) pp. 17273–17286. |
| 43172 |
label |
Bowen, James and Cheneler, David (2012). A dynamic model of the jump-to phenomenon
during AFM analysis. Langmuir, 28(50) pp. 17273–17286. |
| 43172 |
Title |
A dynamic model of the jump-to phenomenon during AFM analysis |
| 43172 |
in dataset |
oro |