The Fabrication And Performance Of Thermal-Integrated Carbon Nanotube Sensor

As a unique one-dimensional nano-structured and large length diameter ratio material, CNT has a very broad space for development. The adsorption of gas molecules can easily change CNT’s electrical properties, which can be detected by signal output circuit. At room temperature, it takes a long time for molecules to desorpt from CNT surface without any extra treatment. Using an external heating device or infrared ultraviolet lights is not convenient, which makes it not practical and limits the application of CNT sensor. In this research, the micro-heater was integrated with carbon nanotube sensing film by micro-nano processing techniques to form an integrated low power-consumption thermal carbon nanotube sensor. The as-fabricated sensor has wide application due to its characteristics of self-desorption 、 small size 、 low power and easy to carry. The layer-structured sensor was made with micro-heater under the carbon nanotube sensing film. The organic polymer Polyimide(PI) was functioned as insulating layer to electricly separate the micro-heater from carbon nanotube sensing film. The testing results showed that when the micro heater was heated up to 100℃, while the power dissipation was 0.43 W, the sensor exhibited excellent desorption performance toward 40 ppm DMMP gas. The time needed for gas molecules to desorpte was less than 50 seconds. The repeatability of the sensor was investigated when the micro-heater was heated up to 100℃.The result showed that the sensor had great performance under the testing of 20 circle gas adsorption and desorption.