Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

MIT's 'electronic nose' could detect explosives, other hazards

29.10.2007
A tiny "electronic nose" that MIT researchers have engineered with a novel inkjet printing method could be used to detect hazards including carbon monoxide, harmful industrial solvents and explosives.

Led by MIT professor Harry Tuller, the researchers have devised a way to print thin sensor films onto a microchip, a process that could eventually allow for mass production of highly sensitive gas detectors.

"Mass production would be an enormous breakthrough for this kind of gas sensing technology," said Tuller, a professor in the Department of Materials Science and Engineering (MSE), who is presenting the research at the Composites at Lake Louise Conference in Alberta, Canada, on Oct. 30.

The prototype sensor, created by Tuller, postdoctoral fellow Kathy Sahner and graduate student Woo Chul Jung, members of MIT's Electroceramics Group in MSE, consists of thn layers of hollow spheres made of the ceramic material barium carbonate, which can detect a range of gases. Using a specialized inkjet print head, tiny droplets of barium carbonate or other gas-sensitive materials can be rapidly deposited onto a surface, in any pattern the researchers design.

The miniature, low-cost detector could be used in a variety of settings, from an industrial workplace to an air-conditioning system to a car's exhaust system, according to Tuller. "There are many reasons why it's important to monitor our chemical environment," he said.

For a sensor to be useful, it must be able to distinguish between gases. For example, a sensor at an airport would need to know the difference between a toxic chemical and perfume, Tuller said. To achieve this, sensors should have an array of films that each respond differently to different gases. This is similar to the way the human sense of smell works, Tuller explained.

"The way we distinguish between coffee's and fish's odor is not that we have one sensor designed to detect coffee and one designed to detect fish, but our nose contains arrays of sensors sensitive to various chemicals. Over time, we train ourselves to know that a certain distribution of vapors corresponds to coffee," he said.

In previous work, designed to detect nitrogen oxide (NOx) emissions from diesel exhaust, the researchers created sensors consisting of flat, thin layers of barium carbonate deposited on quartz chips.

However, the films were not sensitive enough, and the team decided they needed more porous films with a larger surface area.

To create more texture, they applied the barium carbonate to a layer of microspheres, hollow balls less than a micrometer in diameter made of a plastic polymer. When the microspheres are burned away, a textured, highly porous layer of gas-sensitive film is left behind.

The resulting film, tens of nanometers (billionths of a meter) thick, is much more sensitive than flat films because it allows the gas to readily permeate through the film and interact with a much larger active surface area.

At first, the researchers used a pipette to deposit the barium carbonate and microspheres. However, this process proved time-consuming and difficult to control.

To improve production efficiency, the researchers took advantage of a programmable Hewlett Packard inkjet print head located in the MIT Laboratory of Organic Optics and Electronics. The inkjet print head, like that in a regular inkjet printer, can deposit "ink" very quickly and controllably. The special gas sensitive inks used in this work were optimized for "printing" by Amy Leung, an MIT sophomore in chemical engineering.

This allows the researchers to rapidly produce many small, identical chips containing geometrically well-defined gas-sensing films with micrometer dimensions. Patterns, of different gas sensitive inks, just as in a color printer, can be easily generated to form arrays with very little "ink" required per sensor.

In future studies, the team hopes to create large arrays of gas sensitive films with controlled three-dimensional shapes and morphologies.

The research is funded by the National Science Foundation.

Patti Richards | MIT News Office
Further information:
http://www.mit.edu

More articles from Power and Electrical Engineering:

nachricht Researchers pave the way for ionotronic nanodevices
23.02.2017 | Aalto University

nachricht Microhotplates for a smart gas sensor
22.02.2017 | Toyohashi University of Technology

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>