Characterization of Nanopore Processes by Optical Waveguiding in Nanoporous Thin Films

McDonnell Douglas Engineering Auditorium

ChEMS Seminar


Featuring K. H. Aaron Lau, Ph.D., Postdoctoral Fellow, Biomedical Engineering, Northwestern University


Nanoporous thin films have been widely used as templates for fabricating
multifarious material nanostructures and nanoarchitectures. They may
also act as optical slab waveguides if the characteristic dimension of
the pores is much smaller than the wavelength of the light being guided
and scattering losses are small. Waveguide mode excitation is highly
sensitive to the dimensions and optical properties of the waveguide
material. The optical response, morphologies and volume fractionsof both
the pore material and the solid matrix contribute to an effective
refractive index of a nanoporous thin film. Therefore, material
deposition and assembly processes within the nanopores may be
sensitively monitored by characterization of the nanoporous waveguide
mode excitation conditions. If suitable ligands are immobilized on the
pore surfaces, the nanoporous thin film waveguide may also act as a
highly sensitive biosensor, since waveguiding within the nanoporous
structure effectively integrates the optical response over the vast
internal surfaces. Through several examples, including biosensing,
surface-initiated polymerization and polyelectrolyte layer-by-layer
deposition within nanopores, this seminar will discuss the fundamentals
of nanoporous waveguide sensing and highlight the sensitivity and
versatility of the technique.


Dr. Lau earned his Sc.B. and Sc.M. in Materials Engineering, both from
Brown University (2000, 2002). He earned his Ph.D. in Chemistry from the
Johannes Gutenberg University Mainz, Germany, for his research at the
Max Planck Institute for Polymer Research in Mainz (2008). His Ph.D.
research focused on nanostructured thin films and their applications in
waveguide sensing and the generation of (bio)macromolecular structures.
Prior to his Ph.D., he also conducted research at the Danish
Technological Institute in Copenhagen and at the Institute of Materials
Research and Engineering in Singapore. Currently, Dr. Lau is a
postdoctoral fellow at Northwestern University where he is researching
biomimetic polymers for biointerfacial applications.