Preparation and Performance Study of Flexible NiCr/NiSi Temperature Sensors on Mica Substrates

To address the demand for temperature measurement in complex curved surfaces, this study designed and fabricated a high-temperature flexible temperature sensor. The sensor utilizes flexible mica as its substrate. A NiCr/NiSi thermocouple is deposited onto the mica substrate via magnetron sputtering. A protective SiO2 layer and a Ti buffer layer are then applied over the thermocouple to form a multilayer composite structure, significantly enhancing the sensor’s oxidation resistance and stability in high-temperature environments. Performance testing indicates that after 1500 bending cycles, the maximum thermoelectric potential decay rate is 13.4%. Within the temperature range of room temperature to 560 °C, it exhibits a Seebeck coefficient of 17.66 μV/°C, a maximum repeatability error of ±2.17%, a temperature drift of 6.89 °C/h, and a dynamic response time as low as 20 μs. This sensor holds application potential in fields such as thermal management for high-power equipment, thermal runaway monitoring for electric vehicle battery cells, and thermal detection for smart wearable devices.