Silver and copper screen‐printed temperature sensors on flexible substrates: The impact of ink sintering conditions and composition

Fully screen‐printed silver and copper temperature sensors were studied up to 100°C. The influence of the processing conditions and the composition of three silver and one copper commercial inks is analyzed in this study. The curing temperature is extremely relevant to stabilize the initial resistance of silver sensors, especially for those printed with the lowest solid content ink. All printed sensors showed good linear behavior in the range of 25–100°C (R2 > 0.999) except for those fabricated with the lowest solid content silver ink, which also displayed the highest hysteresis and drift. The temperature coefficient of resistance (TCR) obtained for the copper sensors was 3.367 × 10−3 K−1 and for the three silver sensors, it ranged between 2.723 × 10−3 to 2.963 × 10−3 K−1. This TCR is higher than values reported for inkjet‐printed resistive temperature detectors. Overall, this work demonstrates that low‐cost, linear, screen‐printed temperature sensors can be successfully fabricated on flexible substrates. Screen‐printed low‐cost temperature sensors fabricated with three silver and one copper commercial ink on polyimide are analyzed. The effect of the curing time and temperature on the sensors’ performance is studied and compared among silver inks with different compositions. Sensors are characterized in the range between 25ºC and 100ºC, targeting industrial applications.