Low-Cost Paper-Based Wireless Sensor Could Help Detect Explosive Devices

Researchers at the Georgia Institute of Technology have developed a prototype wireless sensor capable of detecting trace amounts of a key ingredient found in many explosives.

The device, which employs carbon nanotubes and is printed on paper or paper-like material using standard inkjet technology, could be deployed in large numbers to alert authorities to the presence of explosives, such as improvised explosive devices (IEDs).


"This prototype represents a significant step toward producing an integrated wireless system for explosives detection," said Krishna Naishadham, a principal research scientist who is leading the work at the Georgia Tech Research Institute (GTRI).

"It incorporates a sensor and a communications device in a small, low-cost package that could operate almost anywhere."


Other types of hazardous gas sensors are based on expensive semiconductor fabrication and gas chromatography, Naishadham said, and they consume more power, require human intervention, and typically do not operate at ambient temperatures. Furthermore, those sensors have not been integrated with communication devices such as antennas.


The wireless component for communicating the sensor information -- a resonant lightweight antenna -- was printed on photographic paper using inkjet techniques devised by Professor Manos Tentzeris of Georgia Tech's School of Electrical and Computer Engineering. Tentzeris is collaborating with Naishadham on development of the sensing device.


The sensing component, based on functionalized carbon nanotubes (CNTs), has been fabricated and tested for detection sensitivity by Xiaojuan (Judy) Song, a GTRI research scientist. The device relies on carbon-nanotube materials optimized by Song.


A presentation on this sensing technology was given in July at the IEEE Antennas and Propagation Symposium (IEEE APS) in Spokane, Wash., by Hoseon Lee, a Ph.D. student in ECE co-advised by Tentzeris and Naishadham. The paper received the Honorable Mention Award in the Best Student Paper competition at the symposium.


This is not the first inkjet-printed ammonia sensor that has been integrated with an antenna on paper, said Tentzeris. His group produced a similar integrated sensor last year in collaboration with the research group of C.P. Wong, who is Regents professor and Smithgall Institute Endowed Chair in the School of Materials Science and Engineering at Georgia Tech.