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 Robot on demand: Mobile machining of aircraft components with high precision
06.12.2016 | Fraunhofer IFAM

nachricht IHP presents the fastest silicon-based transistor in the world
05.12.2016 | IHP - Leibniz-Institut für innovative Mikroelektronik

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>