Aerosol Jet Printing of High-Temperature Bimodal Sensors for Simultaneous Strain and Temperature Sensing Using Gold and Indium Tin Oxide Nanoparticle Inks

Integrating multiple sensing capabilities into a single multimodal sensor greatly enhances its applications for in situ sensing and structural health monitoring. However, the fabrication of multimodal sensors is complicated and limited by the available materials and existing manufacturing methods that often involve complicated and expensive fabrication processes. In this study, a high-temperature bimodal sensor is demonstrated by the aerosol jet printing (AJP) of gold and indium tin oxide nanoparticle inks. The printed bimodal sensor for concurrent strain and temperature sensing possesses a high gauge factor of 2.54 and thermopower of 55.64 μV/°C combined with excellent high-temperature thermal stability of up to 540 °C. Compared to traditional single-modality sensors, the printed bimodal sensor significantly increases the sensing capacity and improves spatial resolution using microscale printed patterns. The study also demonstrates that the strain sensor with an integrated thermocouple enables in situ compensation of the temperature effect on strain sensing, significantly improving strain measurement accuracy at high temperatures. By the combination of AJP with nanomaterial inks, a wide range of multifunctional devices can be developed for a broad range of emerging applications.