Thin polymer films are an integral part of many
emerging nanotechnologies (MEMS, NEMS, NIL)
There is a need for HT measurement platforms that
assess the mechanical properties of thin films and
coatings
Objective
Develop a reliable, high-throughput technique by which the
elastic modulus of thin polymer films can be measured.
Demonstrate the capability of this technique on model systems
that span the full range of polymeric moduli, from MPa to GPa.
Approach
We have established a novel buckling-based metrology
that leverages an elastic buckling instability that occurs upon
compression of a stiff upper film supported by a soft elastic
substrate
The periodicity or wavelength of the buckling
pattern can be related to the moduli of both the upper film
and the elastic substrate:
Results
Small angle light scattering (SALS) enables high-throughput
determination of the buckling wavelength as a function of spatial
position.
Validation studies:
Plasticized PS films
Soft structured films
Numerical Simulation (Finite Element):
Future Directions
Conduct numerical modeling (FEA) on continuous and discrete
gradient to investigate the interaction between adjacent regions.
Extend our buckling-based metrology to probe the mechanical
properties of multilayer film geometries.
Invert the experimental design to enable measurement of soft
materials (e.g., gels) by using employing a sensor film with
known properties (w/ Biomaterials).
NIST Contributors
Christopher M. Stafford, Shu Guo, Arnaud Chiche, Martin Y.M.
Chiang, Bryan D. Vogt
Combinatorial Methods Group
Polymers Division
Materials Science and Engineering Laboratory
