Fabrication of High Efficiency Carbon Nanotube Thin Film Heater by Simple Spray Coating and Substrate Shrinkage Method

The paper presents a flexible thin film heater based on crumpled multi-walled carbon nanotube (MWCNT) fabricated by a simple spray coating and substrate method. The innovative claims include: (1) the large increase in temperature (as high as 200%) at a given input voltage due to the decreased heat loss from CNT junctions, (2) control of the junction density (the number of junctions in a given area) controlled by substrate shrinkage, and (3) localization of temperature profiles via selective substrate shrinkage. We have fabricated the heater with various CNT amount to analyze its impact on the heater properties. The heater heating performance is characterized using an infrared (IR) camera, and the heater's temperature coefficient of resistance (TCR) is analyzed as well. All of fabricated heaters exhibit highly linear TCR up to 200 °C, showcasing that our device can be used to measure the surface temperature. Our findings suggest heating and electrical properties of CNT heaters can be optimized via substrate shrinkage, which could further improve the current state of CNT thin film heaters.