Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Miniature Sandia Sensors May Advance Climate Studies

12.04.2012
Self-sealing valves also increase data reliability for airborne industrial and battlefield gas detection and point-of-contact medicine

An air sampler the size of an ear plug is expected to cheaply and easily collect atmospheric samples to improve computer climate models.

“We now have an inexpensive tool for collecting pristine vapor samples in the field,” said Sandia National Laboratories researcher Ron Manginell, lead author of the cover story for the Review of Scientific Instruments, the often-cited journal of the American Institute of Physics.

The novel design employs a commonly used alloy to house an inexpensive microvalve situated above the sample chamber.

When heated, the alloy — a kind of solder — melts and flows, blocking the inlet hole. When cooled, the alloy resolidifies into an impermeable block that seals the gas sample inside the inert chamber below. Low cost should make widespread distribution of these sensors possible, while the noncontaminating nature of the design helps meet stringent technical requirements.

Better data collection is important because uncertainties in fact-gathering is one reason climate models reach a variety of conclusions. Winds may blow gases toward or away from a sampling site, gas contents at any location may vary by the hour and by the season, and samples collected by containers in the field may evaporate or become corrupted before analysis in a distant laboratory. Compounding the problem are difficulties in widely distributing sensors, which can be heavy, fragile and require expensive tending by humans.

The Sandia phase-change micro-valve sensor is light, cheap, tough, inexpensive to fabricate and simple to operate. It takes in gas in seconds through a tiny hole about the diameter of three human hairs. The hole closes when a tiny, low-energy hotplate on the canister’s surface melts shut the alloy through which the hole passes, sealing it.

Because the little container doesn’t outgas internally, the trapped sample remains uncorrupted until analyzed in the laboratory. The miniature sensor’s simplicity means it could travel in unmanned aerial vehicles (UAVs) or as unmonitored cargo in atmospheric balloons. The poorest countries could afford to play a role in global climate data collection.

It has so many good features that one is tempted to ask, Do you want to drive it off the lot now or accept delivery at home?

Sandia researcher Mark Ivey is interested now. He oversees the operation of sounding balloons that carry sensors skyward for the Department of Energy in Oliktok Point and Barrow, Alaska. The miniature blimps, able to sample particles around which cloud droplets form, are tethered to winches that reel the soaring balloons back in. Getting sensors to Barrow — a place no highway visits — then into the air and back to a laboratory in the lower 48 makes weight and size a factor.

“Smaller, lighter is a big deal for us,” Ivey said.

Manginell’s team plans to submit an atmospheric sampling proposal this spring to NASA for something called “ground-truth measurement.” NASA, he said, “has a ton of satellite data, more than they know what to do with,” but the agency needs to use data from ground-based or airborne sensors that physically sniff the gases reported by satellites to calibrate remote instruments.

NASA and the National Oceanic and Atmospheric Administration (NOAA), who need ground-truth data, have built systems with flask containers using conventional valves that at open flasks and then close them at specific altitudes. However, the flasks are big — perhaps half a liter in size — and heavy, and the valves they require may outgas, ruining the measurements, Manginell said.

Outgassing occurs when the material used for the container releases a gas of its own, contaminating the atmospheric gas trapped in the flask.

The Sandia system “would have 100 of these devices in a package that has a macrovalve on top,” said Manginell. An altimeter sends an electrical pulse that opens the macrovalve to fill the package with air. A small pump builds up pressure, filling the tiny cylinders. “You’d use personal-computer (PC) processors that you can put on a circuit board to operate the miniature system,” he said.

The balloons would have global positioning locators on them. The low weight would make them suitable for balloon and UAV applications. The tiny containers are built of alumina tubing, cheap and more inert than glass.

Data collected by the tiny cylinders also could be used to confirm satellite images of airborne industrial effluents, essential for monitoring cap-and-trade deals.

But not all potential uses are in the upper atmosphere. Geoscientists drill boreholes for oil and to understand how the Earth formed. “It’s hard to build a mass spectrometer to go down a 2-inch diameter borehole,” Manginell said. “We’ve proposed instead to use our miniature samplers outfitted with microvalves to take samples that can be transported pristinely back to the surface and then examined in a lab.”

In medicine, volatile compounds that people and animals emit are indicative of disease states and stress. “Point-of-care medicine, instead of taking a blood sample, could sample a person’s breath,” Manginell said. “Alcohol gives a gross signal but infections have a high volatile content as well.” The bacteria that give cows tuberculosis produce a characteristic signature, for example.

“It would take a miniature pump the size of the last joint of your thumb to collect a sample,” Manginell said. “One can perform on-the-spot detection, but also capture a sample in the miniature chamber to send back to the lab for gold-standard tests.” E coli and anthrax also have volatile signatures, he said.

The detector also could be used by the military to collect and analyze gases on the battlefield.

“We’ve spent a lot of time over the past 15 years doing field analysis for customers: microchemlab work for the military and General Electric, and developing handheld gas detectors. This is just another tool in the toolbox,” Manginell said. “But we were pretty happy that this work proved to be broadly cost-effective.”

The work, featured in the paper, “A Materials Investigation of a Phase-Change Micro-Valve for Greenhouse Gas Collection and Other Potential Applications,” is a cross-department effort.

“This is a little different from what we’ve done in the past,” Manginell said. “The widespread collection of greenhouse gases has to be extremely cheap. So we collected people who have done soldering, brazing and thick-film metallization on ceramics that’s scalable to high-volume production. Some did analytical chemistry to figure out if we were contaminating the sample. Others found the perfect solder mix.”

Sandia researcher Curt Mowry said, “I made sure the solder didn’t contribute any CO2 to the sample that was collected, because then you have a stinky measurement.”

More certainty in data collection is good because of the uncertainties in climate predictions, Manginell said.

“The overwhelming majority of the data seems to point to the fact that there’s warming, but how do you attribute that: Is it natural variation or manmade influence?” he said. “Distributions of our capsules would greatly improve the accuracy of field measurements. You’d have a platform that would be ubiquitous, on planes, UAVs, balloons in countries that can’t ordinarily afford to do these things. In India, it’s hard to make those measurements when you’re concerned with putting food on the table. But for legislation or policy decisions on, say, cap and trade, it’s important to make those measurements accurately.”

Funding came from Sandia’s Laboratory Directed Research and Development (LDRD) program, Manginell said.

“We thought we could do a more ubiquitous job of sensing than anything currently available,” he said.

Despite successful testing of the device, Manginell’s work, like science, is never finished.

“What we need to build next is a normally closed version of the valve that opens when we want it to,” he said. A presealed container would eliminate another possible source of contamination in transit.

Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies and economic competitiveness.

For information about additional climate security work at Sandia, visit the climate section on the Energy, Climate & Infrastructure Security website.

Sandia news media contact: Neal Singer, nsinger@sandia.gov, 505-845-7078

Neal Singer | Newswise Science News
Further information:
http://www.sandia.gov

Further reports about: Advance Climate change Manginell Miniature NASA Sandia Security Forum Sensors UAV climate models greenhouse gas

More articles from Power and Electrical Engineering:

nachricht A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes
20.07.2018 | Science China Press

nachricht Future electronic components to be printed like newspapers
20.07.2018 | Purdue University

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: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>