Flexible thermoelectric cells fabricated by rubbing-in technology with rubber-carbon nanotubes/graphene composites

Abstract

In this research, CNT and graphene-rubber composites based thermoelectric cells were fabricated by using the rubbing-in technology. However, the comparative analysis of both elastic thermoelectric cells was also carried out. The carbon nanotubes and graphene composites with rubber were used as an active layer of thermoelectric cells. The films were deposited over rubber substrate (length 7 mm and width 5 mm) and pressure of (7–12) g/cm2. The electric dependence of the cells i.e., voltage (open-circuited), current (short-circuited), resistance and Seebeck coefficient with respect to averaged temperature (with gradient = 10 °C) was measured in the temperature interval of 30 °C–55 °C. The CNT/Graphene-rubber composite based active layer properties were investigated and results showed that with an increment in average temperature, there is an increase in current and voltage as well. In case of short circuit current, the increase in CNT-rubber and graphene-rubber composites was 1.82 and 4.5 times while an increase in open circuit voltage was 1.75 and 6.5 times, respectively. It was also found, that the graphene-rubber composites cells had a higher thermoelectric coefficient as compared to CNT-rubber thermoelectric cells. These cells can be potentially utilized as flexible and vibrations free thermoelectric sensors for measurement of the gradient of temperature and elastic thermoelectric modules for low power applications. Keywords: Flexible thermoelectric cell, Carbon nanotubes, Graphene, Energy conversion, Rubbing-in technology