Single material thermocouples from graphite traces: Fabricating extremely simple and low cost thermal sensors

Thermocouples are a universal type of thermal sensors routinely used in different applications for the measurement and monitoring temperature. Traditionally, they constructed from two dissimilar conductors. In this work, single material thermocouples fabricated using graphite pencil traces patterned on cellulose paper. The magnitudes Seebeck coefficients grade pencils facilitate successful construction graphite‐only thermocouple sensor. These extremely simple, low-cost, eco-friendly have shown stable reliable sensitivity 7.4 (±0.3) µVK−1, indicating good temperature resolution better than 0.2 K. With advantage simple solvent-free fabrication process, such devices can be developed as cheap, environmentally friendly, disposable sensors.