Fabrication of a Silver-Based Thermistor on Flexible, Temperature-Sensitive Substrates Using a Low-Temperature Inkjet Printing Technique

Abstract

Inkjet printing has been identified as a cost-effective method to fabricate sensors on polymeric substrates. However, substrate materials suitable for printing are limited by the annealing temperature required by conventional inks. In this article, we describe the fabrication of an inkjet-printed thermistor on polyethylene and cellophane substrates that are not thermally compatible with the conventional inkjet printing processes. Fabrication on these substrates is made possible by a novel plasma-based postprint treatment step that limits the substrate temperature to <50 °C. The sensors exhibited a temperature sensitivity of 0.25 Ω°C^-1 that was independent of substrate material. The utility of the fabrication process was demonstrated by fabricating thermistors for common indoor and outdoor applications.