Effects of thermal annealing on SEBS/MWCNT temperature-sensitive nanocomposites for the measurement of skin temperature

The monitoring of skin temperature is essential for many applications, especially in sport and medicine. In this work, a flexible and wearable temperature sensor was obtained thanks to the controlled incorporation of multi-walled carbon nanotubes (MWCNTs) in an elastomeric matrix based on a poly(b-styrene-b-(ethylene-co-butene)-b-styrene) matrix. Thermal annealing at 155°C for 4 hours decreased the percolation threshold of the nanocomposite by about 40% thanks to the strong modification of the copolymer phase structure, which provided a more effective percolative network. The proposed temperature sensor prototype showed a very high linearity (R2 = 0.9987) and reproducibility (standard deviation < 1%) for temperature variations within the physiological regime.