BOSTON Researchers have developed a new low cost sensing material that can be integrated in electronic circuits and can enable smartphones to detect toxic gases within seconds.
Researchers from National Institute for Materials Science in Japan and Massachusetts Institute of Technology (MIT) developed the chemical sensing material whose electrical conductivity dramatically increases when exposed to toxic gases.
They integrated the sensing material into the electronic circuit in a near-field communication (NFC) tag, which is embedded in smart cards like those used to get through train ticket gates.
This technology made it possible for smartphones to quickly (in five seconds) detect toxic gases at a low concentration (10 parts per million).
People in today’s society are subject to risks of being exposed to toxic gases deriving from natural sources (such as volcanic gases), leak accidents or potential acts of terrorism.
Means to easily and quickly detect toxic gases are vital to minimise their harmful effect.
The currently available toxic gas sensors are expensive, bulky, heavy and difficult to operate, and it is not practical to set them at many public locations (for example subways) or for people to carry them around, researchers said.
They developed a low-cost chemical sensing material consisting of a group of carbon nanotubes (CNTs) individually wrapped with supramolecular polymers – clusters of monomers held together through weak interactions.
The material’s electrical conductivity increases up to 3,000 times when it is exposed to electrophilic toxic gases.
CNTs alone are highly conductive materials, but when they are wrapped with supramolecular polymers, which serve as insulators, they become poor conductors.
The supramolecular polymers were designed so that weakly bound sites in the molecules are dissociated when these sites are exposed to toxic gases, causing the wrapping molecules to disassemble, researchers said.
(AGENCIES)
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