Thermoelectric response of a screen printed silver-nickel thermocouple

The lack of inks with adequate properties for the development and construction of a fully printed thermocouple requires the adoption of a different approach. Silver and nickel screen printing inks were selected for the sensing materials, considering their low sintering temperature, required for polymer substrates, and its greatest cost-benefit ratio between the existing materials. This work studied the influence of the sintering conditions on the electrical resistivity of screen printed thin-films and the thermoelectric responses of the Ag-Ni thermocouple printed on polymeric substrates. The printed thin-films were thoroughly characterized by scanning electronic microscopy (SEM) and Energy Dispersive X-ray Spectrometer (EDS), and by thermogravimetric analysis (TGA). The electric properties were assessed by the Van der Pauw method. Also, the thermoelectric response of the printed sensors was evaluated. The Seebeck coefficient of the printed sensors proves that the thermoelectric response wasn’t affected by the sintering level and the achieved surface resistivity. When compared to a commercial sensor (Type-K), although the difference Seebeck coefficient between sensors, the linear behavior between the commercial thermocouple and the printed sensors is very similar.