Abstract - Smart Materials and Sensors

Nanomechanics, Frizzy Hair, Beetles, Wine, and Oil Sands
Thomas Thundat
Professor and Canada Excellence Chair
Department of Chemical and Materials Engineering, University of Alberta, Canada
Interfacial phenomena are fundamental to many areas of science and engineering. Humid
air creating havoc on gorgeous hairstyles is a common observation. Nature has perfected
many different ways to utilize the interfacial phenomena for its own benefits. A beetle in
the dessert collect drinking water from air by condensation on specifically patterned shell
surface. A lotus leave cleanses itself of dust when it rains because of its
superhydrophobic structures on its leaves. A glass of wine forms tears due to Marangoni
effect. Some butterflies change their color to adapt to the environment by rearranging the
periodicity of the scales on their wings. These observations, often occurring at nanoscale,
can be exploited for developing sensors, devices for collecting and pre-concentrating
molecules, and separating oil from oil sands. I will discuss myriads of observations of
natural phenomena that people have made over the years, which can be the basis for a
plethora of highly sensitive chemical and biological sensors and pre-concentrators for
targeted analytes. Despite the high sensitivity that can be achieved by exploiting the
nanomechanical effects, obtaining chemical selectivity still remains elusive. I will
address the challenges of molecular selectivity in nanosensors and discuss ways by which
we can overcome the selectivity challenge. I will also discuss standoff sensors.