TransForum Vol. 6, No. 1

Market-Ready Hydrogen Sensor Promises "Ultra" Performance

Argonne's novel hydrogen sensor.

"Ultra" means "beyond the ordinary" – and Argonne's new ultrafast and ultrasensitive hydrogen sensors deliver on that promise. Michael Zach, a Glenn Seaborg Postdoctoral Fellow in Argonne's Materials Science Division (MSD) and his colleagues Tao Xu and Zhili Xiao, also of MSD, have produced the tiny new sensors, which are based on nanostructured self-assembled palladium thin films.

The ultrafast and ultrasensitive sensors discovered at Argonne are true examples of a ready-for-market product of nanotechnology. "Our discovery is an enabling technology that will provide a fundamental safety component for our emerging hydrogen economy," states Zach. "They are much faster, more sensitive, simpler, and less expensive than any other existing hydrogen-sensing system. They also have low power requirements and require only simple monitoring of resistance, making them robust for many applications," he explains. The sensors can be manufactured by using easy, scalable techniques for mass production, which minimizes their cost.

As our nation pursues new fuels and technologies, hydrogen-based technologies will become more widespread in transportation – but using hydrogen involves safety considerations different from those of other fuels. Therefore, the need for cost-effective and reliable hydrogen sensors is growing, and Argonne's sensor may well set an industry standard for sensor performance in transportation and other applications. The sensor developed by Zach and his colleagues can sense hydrogen at extremely low concentrations – as low as 25 parts per million – and very rapidly (in less than 70 milliseconds) without elaborate amplification of the signal. Using only processes that are compatible with mass production and routinely used in the semiconductor industry, they have created the world's fastest commercially producible hydrogen sensor. This simple, robust technology eliminates the need for heavy, bulky, and energy-demanding methods for detection. "And by adding electronic devices to activate safety systems when thresholds of hydrogen concentration have been reached, our technology can truly make a hydrogen economy safer than our fossil-fuel-driven economy," predicts Zach.

Here's a possible scenario: As hydrogen leaks from a damaged, malfunctioning, or improperly sealed automotive system, it will normally quickly dissipate to below the 4% lower limit of flammability. By using a sensor system that can detect a minor leak at one one-thousandth of a flammable concentration, it could alert the driver via a dashboard indicator light long before a more significant leak would develop. Says Zach, "If there's a more significant leak, or if hydrogen is leaking into an enclosed space where the concentration could build to greater than 4%, a very dangerous situation is about to occur. It's imperative to have an extremely rapid sensor that can shut off hydrogen at the tank in less than 100 milliseconds. When such safety devices are used, we can make hydrogen-powered vehicles much safer than the gasoline-fueled vehicles in use today."

Makel Engineering's electronics package for Argonne's sensor. Makel has developed a robust electronics package that is completely compatible with Argonne's sensor technology. The image on the left shows the circuitry that has been developed to provide threshold detection and continuous monitoring of the sensor condition. The arrows show the location of Argonne's sensing element. The image on the right shows the finished product, complete with the wiring harness and the packaging needed for installation in automobiles.

Argonne's novel technology has sparked considerable interest from industry – companies interested in the technology range from start-ups to major international automobile manufacturers. For example, Argonne has teamed with Makel Engineering (Chico, California) to commercialize these sensors. "No other commercial technology works as fast, is as sensitive, or is as efficient as Argonne's technology, and those are some of the reasons why Makel Engineering has signed an exclusive license agreement with Argonne," asserts Zach.

Makel, a leader in high-quality hydrogen sensing for NASA's shuttle missions and other notable applications, will be employing Argonne's sensor design in a package developed for the automotive industry. This package combines robust signal processing, threshold detection, and redundant engineering to ensure safety. Combining Makel's proven electronic packages with Argonne's nanotechnology-based sensing elements will yield a simple, cost-effective, and highly marketable hydrogen-sensing unit. Makel has also secured funding for product development through Ohio-based Edison Materials Technology Center (EMTEC). "EMTEC will help to develop market-ready products based on Argonne's technology that will be widely commercialized in our automobiles and the fuel cells powering our homes," Zach notes.

With its ultrafast and ultrasensitive hydrogen sensor, Argonne is helping the nation meet its energy needs safely, cleanly, and responsibly. According to Zach, "Makel Engineering's confidence in Argonne's technology and EMTEC's product development expertise will help us deliver the technology needed to help ensure a safe and prosperous future."

Argonne's extraordinary sensor was recognized with an R&D 100 award in 2006. The sensor's research was sponsored by DOE's Office of Science and Office of Basic Energy Sciences, State of Illinois, Makel Engineering, and Edison Materials Technology Center.

September 9, 2006