Nickel Based RTD Fabricated via Additive Screen Printing Process for Flexible Electronics

A novel nickel (Ni)-based resistance temperature detector (RTD) was successfully developed for temperature monitoring applications. The RTD was fabricated by depositing Ni ink on a flexible polyimide substrate using the screen printing process. Thermogravimetric analysis was performed to study the thermal behavior of the Ni ink, and it was observed that the Ni ink can withstand up to 200 °C before the decomposition of the binder in the ink system. Scanning electron microscopy and white light interferometry were used to analyze the surface morphology of the printed Ni. X-ray diffractometry was used to obtain structural information, phase, and crystallite size of the deposited Ni nanoparticles. Energy dispersive X-ray spectroscopy was used to obtain semi-quantitative information of the elements present in the fabricated RTD. The capability of the RTD to detect temperatures varying from -60 °C to 180 °C, in steps of 20 °C, was investigated at a constant relative humidity of 20%RH. The results of the RTD demonstrated a linear response with resistive changes as high as 113% at 180 °C when compared with its base resistance at -60 °C. An average TCR of 0.44%/°C was calculated for the printed RTD with a response time of <;10 s. The obtained results demonstrated the feasibility of employing Ni on flexible substrates for the development of flexible temperature sensors.