Apr 12 2019
Vehicles can be powered by hydrogen—a clean, renewable energy carrier that releases only water as the byproduct.
Chalmers researchers Ferry Nugroho, Iwan Darmadi, Christoph Langhammer, Lucy Cusinato och Anders Hellman. (Image credit: Chalmers University of Technology)
Regrettably, when this gas is combined with air, it becomes highly flammable, and hence extremely effective and efficient sensors are required. Now, a team of researchers from Chalmers University of Technology, Sweden, has reported the world’s first hydrogen sensors that meet the upcoming performance targets for use in vehicles powered by hydrogen.
The breakthrough results have been recently reported in the prominent scientific journal Nature Materials. The finding is an optical nanosensor enclosed in a plastic material. The novel sensor functions on the basis of an optical phenomenon called a plasmon, which takes place when metal nanoparticles are lighted up and visible light of a certain wavelength is captured. When there is a change in the amount of hydrogen in the environment, the sensor will merely change color.
The plastic surrounding the compact sensor is not provided simply for protection, but it also works as a major component. It boosts the response time of the sensor by expediting the uptake of the hydrogen gas molecules within the metal particles where they can be identified. Simultaneously, the plastic serves as an effective barricade to the environment, making sure that molecules do not enter and deactivate the sensor. As a result, the sensor can work without any disturbance and also highly efficiently, allowing it to meet the stringent requirements of the automotive sector—to have the potential to detect 0.1% of atmospheric hydrogen within a second.
We have not only developed the world’s fastest hydrogen sensor, but also a sensor that is stable over time and does not deactivate. Unlike today’s hydrogen sensors, our solution does not need to be recalibrated as often, as it is protected by the plastic.
Ferry Nugroho, Researcher, Department of Physics, Chalmers University of Technology
When Ferry Nugroho was a PhD student, he and his supervisor Christoph Langhammer noted that they were on to something big. However, when they came across a scientific article, which cited that none had succeeded in attaining the rigorous response time needs imposed on hydrogen sensors for upcoming hydrogen cars, they began to test their own sensor. The duo eventually realized that they were just a single second from the target—without even attempting to improve it. Originally meant as a barrier, the plastic not only made the job better which superseded their imagination but also made the sensor faster. The finding resulted in an intense period of theoretical and experimental work.
In that situation, there was no stopping us. We wanted to find the ultimate combination of nanoparticles and plastic, understand how they worked together and what made it so fast. Our hard work yielded results. Within just a few months, we achieved the required response time as well as the basic theoretical understanding of what facilitates it.
Ferry Nugroho, Researcher, Department of Physics, Chalmers University of Technology
It is very difficult to detect hydrogen. For instance, the gas is odorless and invisible yet volatile and highly flammable. It needs just 4% of hydrogen in the air to create oxyhydrogen gas, at times called knallgas. This gas tends to ignite even at the slightest spark. Therefore, to make the future hydrogen cars and the related infrastructure adequately safe, it must be feasible to detect very small levels of atmospheric hydrogen. The sensors have to be so fast that leaks can be quickly detected much before a fire starts.
It feels great to be presenting a sensor that can hopefully be a part of a major breakthrough for hydrogen-powered vehicles. The interest we see in the fuel cell industry is inspiring.
Christoph Langhammer, Professor, Department of Physics, Chalmers University of Technology
Even though the goal is to mainly utilize hydrogen as an energy carrier, the sensor also provides many other possibilities. For example, highly efficient hydrogen sensors are required in the chemical, the electricity network, and the nuclear power industries and they can also help in enhancing medical diagnostics.
The amount of hydrogen gas in our breath can provide answers to, for example, inflammations and food intolerances. We hope that our results can be used on a broad front. This is so much more than a scientific publication.
Christoph Langhammer, Professor, Department of Physics, Chalmers University of Technology
Over time, it is believed that the sensor could be developed in series in an efficient way, for instance with the help of 3D printer technology.
The study was funded by the Swedish Foundation for Strategic Research, within the framework of the Plastic Plasmonics project.