Optimizing electrode structure of carbon nanotube gas sensors for sensitivity improvement based on electric field enhancement effect of fractal geometry.

With the rapid development of carbon nanotubes gas sensor, the sensitivity of the sensing response is becoming more and more demanding. Different from the traditional studies on gas-sensitive materials, this paper combines the microscopic dimensional effects and physical properties of fractal geometry theory from the structure and morphology of sensor devices. The electrode structures of carbon nanotubes gas sensor is designed and optimized by Hilbert-Piano curve. Simulation experiments demonstrate that the electric field intensity and hot spot distribution of the fractal electrode are superior to those of the traditional interdigital electrode. Moreover, a novel chemiresistive gas sensor is fabricated combining the characteristics of carbon nanotubes and fractal geometry, and a test with exposure to nitric oxide showed that the sensors with fractal electrode structures improved the gas sensing sensitivity over sensors with traditional geometrical structures. It provides a new idea for the exploration of gas sensing technology.