A MEMS-based ionization gas sensor using carbon nanotubes and dielectric barrier

We have demonstrated here the successful operation of an ionization gas sensor with gap spacing 2~10 mum and using CNTs (carbon nanotubes) as the electrode material. By set up an appropriate threshold current, the application of less than 20 V DC bias could generate electric field enough to effectively ionize various gases in atmospheric pressure. Working by the fingerprinting ionization characteristics of distinct gases, the sensor can effectively distinguish several gases by their various breakdown voltages and serves as an effective human breath monitor. TiO₂ dielectric barrier is introduced to the discharging system to improve the performance of the device. Experimental tests prove that with the dielectric barrier discharge mechanism has improved both the stability and ionization capability of the device.