《wireless gas sensor using CNT_PMMA thin film chemiresistor》.pdf

INSTITUTE OF PHYSICS PUBLISHING SMART MATERIALS AND STRUCTURES Smart Mater. Struct. 13 (2004) 1045–1049 PII: S0964-1726(04)82882-9 A compact wireless gas sensor using a carbon nanotube/PMMA thin film chemiresistor 1 1 1 Jose K Abraham , Biju Philip , Ashwin Witchurch , Vijay K Varadan1 and C Channa Reddy2 1 Center for Engineering of Electronics and Acoustics Materials and Devices, Pennsylvania State University, University Park, PA 16802, USA 2 The Huck Institute of Life Sciences, Pennsylvania State University, University Park, PA 16802, USA Received 16 February 2004, in final form 17 June 2004 Published 6 August 2004 Online at stacks.iop.org/SMS/13/1045 doi:10.1088/0964-1726/13/5/010 Abstract The design and development of a compact wireless gas sensor with a surface modified multiwalled carbon nanotube (f -CNT) chemiresistor as the sensing element is presented in this paper. f -CNT/polymer composite sensing film is patterned on a printed circuit board and is integrated to the wireless system. The change in resistance of the CNT/polymer composite film due to exposure of different gases is utilized as the principle of this gas sensor. The response for different organic vapors are evaluated and it is observed that the f -CNT/PMMA composite film shows fast response and change in resistance of the order of 102–103 due to its surface modification. (Some figures in this article are in colour only in the electronic version) 1. Introduction and mechanical properties. These properties make them potential candidates for building blocks of active materials Advancements in microtechnology and