doi:10.1038/nindia.2011.122 Published online 23 August 2011
Researchers have developed a polyester-based biosensor that can be fitted into the fabric of garments to detect diseases of the heart, lungs and liver.
Organic polymers, widely used as industrial sensors, decompose and have a short shelf life. To devise a sensor that is immune to decomposition and compatible with cloth, the researchers investigated the use of polyester-based yarn. They fabricated a textile-based sensor by halting the polycondensation process midway to produce thermally unstable partially oriented yarn (TUPOY) sensors.
They tested the TUPOY sensors in detecting diseases among 1,000 individuals and compared the results with those of foam-based and metallic sensors. They measured wave patterns generated by the pulse of each subject's radial artery. When the arterial pulse wave strikes the sensor, the energy of the wave produces an internal thermal excitement, which can be measured. The thermal excitement varies for different kinds of diseases and normal conditions.
The researchers identified eight common wave patterns and linked them distinctly to diseases such as heart disease, cirrhosis of the liver, tuberculosis, asthma and arthritis. Unlike metallic sensors, no external power is needed to operate these devices; a TUPOY sensor generates heat when an external wave strikes its surface. Owing to its unstable nature, the textile sensor exhibits metallic properties.
"TUPOY sensors are cheaper than silicon sensors and far cheaper than sensors made from carbon nanotubes and graphene," says H. D. Mustafa, one of the researchers. This is an intelligent textile sensor that could also be exploited to yield next-generation processors for computing, he adds.
The authors of this work are from: Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai, and Department of Electrical Engineering, Indian Institute of Technology Hyderabad, India.
- Karamchandani, S. et al. Thermally unstable intelligent polymer textile biosensors. Sensor. Actuator. B 156, 765-772 (2011) | Article |