Design and Testing of a Wireless Portable Carbon Nanotube-Based Chemical Sensor System

The design and preliminary testing results of a wireless portable carbon nanotube-based chemical sensor system are presented in this paper. The overall sensor system consists of a chemical sensor module, a microcontroller-based data acquisition module, a multiplexer and constant current source module, and a wireless communication module. The chemical sensor module is based on use of an interdigited electrode (IDE) configuration. A layer of single-walled carbon nanotubes (SWNTs) is laid on the IDE electrodes. Chemical sensing is based on detection of changes in the conductivity of the SWNT network. The system has 32 channels of chemical sensing elements. It is self-contained and portable, and wirelessly transmits measurement data to a PC via an 802.11b wireless LAN. Preliminary results on chemical detection and chemical selectivity are described.