Nanosensors could detect cracks in bridges, aircraft
PORTLAND, Ore.  -  Nanocomposites are being developed to monitor the safety of bridges and aircraft by embedding nanotubes into sensors that change their conductivity when cracks or other structural defects occur.
The Queensland University of Technology (Brisbane, Austrailia) said it will conduct the research in cooperation with the four other Australian universities.
"It looks like a piece of thin black sheeting, but it can act as a sensor to monitor the strength of structures such as bridges, aircraft and ships," said researcher Cheng Yan. The polymer nanocomposite contains carbon nanotubes which change the conductivity of the material when cracks appear in structures where it is used. By monitoring the electrical conductivity of the material, early detection of structural faults may be possible.
"Structures like these can be monitored constantly for cracks, metal fatigue and warping," said Yan. "Repairs can be carried out before the damage becomes critical."
The nanocomposite is strong but lightweight since nanotubes are 1,000 times stronger than steel but are extremely light due to their nanoscale dimensions. The composite material could be applied like sheets of fiberglass which conform to the shape of the surface, making them less expensive than alternative active monitors that use conventional sensors, Yan claimed.
Yan's research team is also cooperating with other materials engineers to make other types of polymers using various nano-sized fillers that would increase their conductivity, strength and durability.