Fabrication of an Ionization Gas Sensor using Suspended Carbon Nanotubes

Ionizations sensors work by identifying the fingerprints of various gases by their ionization characteristics. However, they are limited in application by their size, high power consumption and high voltage characteristics. In this work, a Microelectromechanical systems (MEMS) based suspended Carbon Nanotube (CNT) ionization sensor fabricated by a low temperature surface micromachining process has been presented. The device consists of a CNT beam suspended over a metal electrode at a height of 3.6 μm. The CNT beam is made of billions of individual nanotubes that are randomly aligned horizontally as compared to conventional vertically grown aligned CNT ionization sensors. The sensor response to various gases was tested to determine the sensing characteristics. The resultant sensor demonstrated excellent sensing capabilities for various gases.