New sensors will let smartphones detect toxic gases

MIT researchers have developed new low-cost chemical sensors that can enable smartphones or other wireless devices to detect trace amounts of toxic gases.

Using the sensors, researchers hope to design lightweight, inexpensive radio-frequency identification (RFID) badges to be used for personal safety and security.

such badges could be worn by soldiers on the battlefield to rapidly detect the presence of chemical weapons

The sensor is a circuit loaded with carbon nanotubes, which are normally highly conductive but have been wrapped in an insulating material that keeps them in a highly resistive state, researchers said.

When exposed to certain toxic gases, the insulating material breaks apart, and the nanotubes become significantly more conductive, they said.

This sends a signal that is readable by a smartphone with near-field communication (NFC) technology, which allows devices to transmit data over short distances.