The final frontier
team shares grant from NASA for biosensor research
teams of local researchers — from Princeton, Rutgers
University and Drexel University in Philadelphia — will
receive during the next three years a combined $1.8 million
from NASA for research applicable to space exploration.
|Chemical engineering professor Ilhan Aksay
and a team of University faculty and students are
developing biological sensors that may be used by
Princeton chemical engineering professors Ilhan Aksay
and Jeffrey Carbeck, Princeton graduate student Chris Martin,
Jessica Jarvis '01 and two Drexel physicists compose one
research team. With a $1.3-million grant, the group is
constructing and refining experimental biological sensors.
Rutgers professor Michael Gershenson leads the second
team, which is receiving $500,000 from NASA. His team is
developing more advanced bolometers, which are instruments
used to detect deep-space electromagnetic radiation. NASA may
use these instruments to increase understanding of how star
According to Aksay, the Princeton-based
project evolved last year when his group was working to
identify the types of biological species that live in water
and in air, including those that live in the human body.
Aksay said members of his group realized that once
they could identify biological presences with a small device,
they could construct a sensor that would be implanted in the
body. This sensor would then relay information about those
biological presences — such as specific molecules or viruses —
to an outside monitor.
Carbeck said the possibility of
long-distance monitoring of the human body's inner environment
piqued NASA's interest because it would allow astronauts'
health to be examined more closely while they were in space.
Describing the sensor's construction and function,
Aksay said a cantilever — a projecting support anchored by one
side — would offer binding sites for the specific biological
product being monitored. When molecules bind to proteins
embedded in the cantilever's surface, they cause an electric
signal to be sent back from the sensor to a monitor.
"Visualize a diving board like in the Olympics," Aksay
said. He explained that the cantilevers in his team's sensors
would not bend, but would vibrate with a certain resonance
Returning to the diving board comparison,
he said, "The resonance frequency depends on the weight on the
diving board. We propose to make a diving board 100 times
smaller than [the diameter of] a human hair and measure the
resonance frequency when something binds to it."
Carbeck said his team has a strategy for using the
devices in a laboratory setting, but he believes challenges
would arise if the sensors were implanted in a living system.
He noted, however, that the step is probably beyond the scope
of the current project.
Aksay's team now is grappling
with the problem of boosting the sensors' sensitivity.
Aksay said with their present technology, the
scientists can increase the surface area where biological
molecules can bond to the sensor, thus increasing its
sensitivity. With the addition of a microscopically thin,
porous gel coat, Aksay said the total surface area of the
cantilever becomes about 1,000 square meters.
is basing her senior thesis on the viability of using such a
gel coat to boost sensor sensitivity. She and the other
members of the team said the group will continue to refine its
techniques and materials with the three-year grant from NASA.
"Making [the cantilevers] is a long project, so we are
focusing on the fundamental issues," Aksay said.