Scaling down sensors

Engineers at MIT are developing a tiny sensor that could be used to detect minute quantities of hazardous gases, including toxic industrial chemicals and chemical warfare agents, much more quickly than current devices.

To develop the sensor, the researchers have taken a gas chromatograph and mass spectrometer and shrunk them to fit into a device the size of a computer mouse. Eventually, the team, led by MIT Prof Akintunde Ibitayo Akinwande, plans to build a detector about the size of a matchbox.

'Everything we're doing has been done on a macro scale. We are just scaling it down,' said Akinwande, a Prof of electrical engineering and computer science.

The gas chromatograph and mass spectrometer identify gas molecules by their electronic signatures. Current versions of such machines are around 40,000 cubic centimetres and are about the size of a full paper grocery bag. They take about 15 minutes to produce results but the new, smaller version produces results in about four seconds.

Scaling down gas detectors makes them much easier to use in a real-world environment, where they could be dispersed in a building or outdoor area. Making the devices small also reduces the amount of power they consume and enhances their sensitivity to trace amounts of gases, Akinwande said.

He is leading an international team that includes scientists from Cambridge University, the University of Texas at Dallas, Clean Earth Technology and Raytheon, as well as MIT.

The device, which the researchers plan to have completed within two years, could be used to help protect water supplies or for medical diagnostics, as well as to detect hazardous gas in the air.

The research, which started three years ago, is funded by the Defense Advanced Research Projects Agency and the US Army Soldier Systems Center in Natick, Massachusetts.