Tiny wireless sensing device alerts users to chemical vapours

Researchers have developed a small electronic sensing device that can alert users wirelessly to the presence of chemical vapours in the atmosphere.
The technology, which could be manufactured using familiar aerosol-jet printing techniques, is aimed at myriad applications in military, commercial, environmental, healthcare and other areas, said researchers at Georgia Tech Research Institute (GTRI).
The current design integrates nanotechnology and radio-frequency identification (RFID) capabilities into a small working prototype.
An array of sensors uses carbon nanotubes and other nanomaterials to detect specific chemicals, while an RFID integrated circuit informs users about the presence and concentrations of those vapours at a safe distance wirelessly.

Because it is based on programmable digital technology, the RFID component can provide greater security, reliability and range - and much smaller size - than earlier sensor designs based on non-programmable analog technology.
The present GTRI prototype is 10 centimetres square, but further designs are expected to squeeze a multiple-sensor array and an RFID chip into a one-millimetre-square device printable on paper or on flexible, durable substrates such as liquid crystal polymer.

"Production of these devices promises to become so inexpensive that they could be used by the thousands in the field to look for telltale chemicals such as ammonia, which is associated with explosives," said Xiaojuan Song, a GTRI senior research scientist and principal investigator on the project.

"This remote capability would inform soldiers or first responders about numerous hazards before they encountered them," Song said.
Wireless sensors could also be valuable for identifying and understanding air pollution, she said.
Inexpensive sensors that detect ammonia and nitrogen oxides (NOx) could be fielded in large numbers, giving scientists increased knowledge of the location and intensity of pollutants.
The present prototype contains three sensors along with an RFID chip.
Future devices for field use might contain a much larger number of sensors based on various nanomaterials - including carbon nanotubes, graphene and molybdenum disulfide - depending on the types of chemicals to be detected.