Development and evaluation of temperature sensors for textile integration

In this paper we report an approach to fully integrate micro fabricated sensors into textiles. We first developed platinum resistance temperature sensors (RTDs) on 500 ¿m-wide, 67.5 mm-long plastic stripes. After completing the sensor fabrication, we used a dicing saw to separate individual sensors by cutting the plastic foil into stripes, each containing an individual sensor and connecting lines. The resistance of the RTDs was 665 ¿ +/- 10 ¿ at room temperature. The temperature coefficient of the RTDs is 0.00223 K^-1 with a the sensitivity of 1.52 ¿/°C at a drive current of 500 ¿A. Cutting the substrate did not affect the sensor functionality. We then tested the influence of strain on the stripe RTDs signal using a pulling tester to apply tensile strain. Longitudinal strain resulted in metal line break after 2 N applied force (at an elongation of 5%) and in breaking of the Kapton stripe at 8 N applied force. Single sensor stripes spaced 10 mm apart were integrated into a textile band using a commercial band weaving machine.