In comparison to previously designed hydrogen sensors, which are rigid and use expensive, pure palladium, the new sensors are bendy and use single-walled carbon nanotubes (SWNTs) to improve efficiency and reduce cost. The development of these hydrogen sensors will help to ensure economical, environmental and societal safety, as the nation is realizing the potential for a more hydrogen-based economy.Yugang Sun and H. Hau Wang, researchers in Argonne's Center for Nanoscale Materials and Materials Science Division, respectively, fabricated the new sensing devices using a two-step process separated by high and low temperatures. First, at around 900 degrees C, researchers grow SWNTs on a silicon substrate using chemical vapor deposition. Then, researchers transfer the SWNTs onto a plastic substrate at temperatures lower than 150 degrees C using a technique called dry transfer printing.According to Sun, these sensors exhibit excellent sensing performance in terms of high sensitivity, fast response time and quick recovery, and the use of plastic sheets reduces their overall weight and increases their mechanical flexibility and shock resistance. The sensors are also able to be wrapped around curved surfaces, and this proves useful in many applications, notably in vehicles, aircraft and portable electronics.