– In a world with an intensified need for security,
Case Western Reserve University researchers are developing
materials that could make consumers less susceptible
to product tampering or failures. Using a mixture
of conventional polymers with small amounts of tailored
fluorescent dyes, Case researchers have discovered
that the dyes function as natural, molecular sensors,
creating light-emitting polymer blends that show mechanical
stress by changing colors when a material is deformed.
The technology could be useful in a variety of applications
that range from early internal failure indicators
in machinery and anti-counterfeiting elements to tamper-resistant
packaging of food or medicines. Their research findings
have appeared in several scholarly publications, most
recently the Journal Chemistry of Materials. The research
is being funded by the National Science Foundation
and industry sources.
Weder, associate professor of macromolecular science
and engineering at the Case School of Engineering,
and graduate engineering students Brent Crenshaw and
Jill Kunzelman are leading experiments in their lab
on the Case campus to further this technology. Crenshaw,
who has been working on the project for two years,
points out that "only a small amount of dye is
needed to make the polymer glow and that the polymer
blend's color contrast upon deformation is unparalleled."
a first-year student, says it would be gratifying
one day to "see this technology used in everyday
thought isn't far-fetched. Imagine being on a bass
boat or hip-deep in a beautiful river doing some fishing
when a colorful light emits from under the water –
it's either time to reel in that largemouth bass quickly
or attach another lure to your fishing pole. Weder's
team created lab samples of a "smart" fishing
line based on light-emitting polymer materials. The
color of the line indicates when it's been stressed
too much. Weder, himself an avid fisherman, is especially
proud of that work.
research team reports that they have successfully
blended tailored but readily available fluorescent
dyes in minimal concentrations into standard polymers,
such as polyethylene and polypropylene, and discovered
that the dyes can serve as built-in sensors, which
change their fluorescent color and allow the researchers
to trace the deformation of the material.
says he is excited by the application potential for
this simple, yet groundbreaking technology his group
is so trivial, yet novel at the same time," Weder
said. "No one has done this."
from Crenshaw and Kunzelman, Weder also employs two
other graduate students, two postdoctoral researchers
and four engineering undergraduates on his research
addition, faculty and students in Case's department
of macromolecular science and engineering are working
on more than 20 projects involving functional polymers,
according to Alex Jamieson, professor and chair of
the department. Those projects include polymers for
membranes in fuel cells, electronic polymers with
semiconducting properties and polymers for biofunctional
applications, such as those related to drug delivery
or biosensors. Weder's deformation sensor technology
project is one of the department's forays into photonic
says he's intrigued by Weder's research into deformation
sensor technology. "It's a novel approach to
developing polymeric blends that are sensitive to
deformation," he said. "It's a simple, yet
very sensitive technique."
exciting aspect of Weder's research is how straightforward
it may be to commercialize.
applicable dyes are affordable, easily made and can
be used in concentrations as low as 0.1 percent,"
potential wherever polymers fulfill a structural function,"
he added, citing tamper-evident packaging tape as
an example. "We're at a level of sophistication
that would allow us to produce a simple product now."
now, these applications are still possibilities. But,
Weder adds, with further commercial development, they
could become reality in our everyday lives.
Contact: Laura Massie
Case Western Reserve University
About Case Western Reserve University
Case is among the nation's leading research institutions.
Founded in 1826 and shaped by the unique merger of
the Case Institute of Technology and Western Reserve
University, Case is distinguished by its strengths
in education, research, service, and experiential
learning. Located in Cleveland, Case offers nationally
recognized programs in the Arts and Sciences, Dentistry,
Engineering, Law, Management, Medicine, Nursing, and
Social Sciences. The Case School of Engineering is
celebrating its 125th anniversary in 2005.