Fabrication and investigation of carbon nanotubes- p -Bi 2 Te 3 -textile composite based temperature gradient sensors

The multiwalled carbon nanotubes- p -Bi 2 Te 3 -cotton textile composite based flexible thermoelectric cells have been designed, fabricated, and characterized for sensing temperature gradient. These cells were fabricated by rubbing-in technology. The textile sheet played the role of substrate as well. The Seebeck coefficient, thermoelectric short-circuit current and resistance dependence on temperature were investigated. It was observed that on increasing temperature in the range of 301 to 351 K the Seebeck coefficient increased by 1.2 times and the short-circuit current increased by 7.0 times, while the resistance of the cells decreased by 1.25 times. Thermoelectric cells can be used for the measurement of the gradient of temperature and as a low power converter of heat energy into electric. Main advantages of the fabricated thermoelectric cells are the following: natural textile substrate, flexibility, low-cost thermoelectric materials, and technology of fabrication, relatively and sufficiently high value of the Seebeck coefficient. The MWCNTs- p -Bi 2 Te 3 -textile composite based cells can be used as resistive temperature sensor due to their quasi-linear resistance-temperature behavior. These cells may also work as multifunctional devices.