title: Wireless sensors and sensor networks for homeland security applications.
abstract: New sensor technologies for homeland security applications must meet the key requirements of sensitivity to detect agents below risk levels, selectivity to provide minimal false-alarm rates, and response speed to operate in high throughput environments, such as airports, sea ports, and other public places. Chemical detection using existing sensor systems is facing a major challenge of selectivity. In this review, we provide a brief summary of chemical threats of homeland security importance; focus in detail on modern concepts in chemical sensing; examine the origins of the most significant unmet needs in existing chemical sensors; and, analyze opportunities, specific requirements, and challenges for wireless chemical sensors and wireless sensor networks (WSNs). We further review a new approach for selective chemical sensing that involves the combination of a sensing material that has different response mechanisms to different species of interest, with a transducer that has a multi-variable signal-transduction ability. This new selective chemical-sensing approach was realized using an attractive ubiquitous platform of battery-free passive radio-frequency identification (RFID) tags adapted for chemical sensing. We illustrate the performance of RFID sensors developed in measurements of toxic industrial materials, humidity-independent detection of toxic vapors, and detection of chemical-agent simulants, explosives, and strong oxidizers.
authors.affiliation: General Electric Global Research Center, Niskayuna, NY, USA.
authors.forename: Radislav A
authors.initials: RA
authors.lastname: Potyrailo
authors.forename: Nandini
authors.initials: N
authors.lastname: Nagraj
authors.forename: Cheryl
authors.initials: C
authors.lastname: Surman
authors.forename: Hacene
authors.initials: H
authors.lastname: Boudries
authors.forename: Hanh
authors.initials: H
authors.lastname: Lai
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Slocik
authors.forename: Nancy
authors.initials: N
authors.lastname: Kelley-Loughnane
authors.forename: Rajesh R
authors.initials: RR
authors.lastname: Naik