The development of full displacement field measurements as an alternative to the optical
lever technique to measure the mechanical response for microelectro-mechanical
systems components in their environment calls for a modeling of chemically-induced
mechanical fields (stress, strain, and displacements). As these phenomena usually
arise from species adsorption, adsorbate modification or surface reconstruction, they
are surface-related by nature and thus require some dedicated mechanical modeling.
The accompanying mechanical modeling proposed herein is intended to represent the
chemical part of the system free energy and its dependence on the surface amount. It
is solved in the cantilever case thanks to an asymptotic analysis, and an
approached closed-form solution is obtained for the interfacial stress field.
Finally, some conclusions regarding the transducer efficiency of cantilevers are
drawn from the energy balance in the accompanying model, highlighting
the role of surface functionalization parameters in micromechanical sensors
engineering.
MIC — Department of Micro and
Nanotechnology NanoDTU
Technical University of Denmark
Ørsteds Plads, Bygning
345 east DK-2800 Kgs.
DK-2800 Lyngby
Denmark
