image: KAUST's new hydrogen sensor is ultra-sensitive, fast, and energy-efficient. It can detect 192 ppb hydrogen in complex gas mixtures in under a second. © 2025 KAUST.
Credit: © 2025 KAUST.
Hydrogen is a clean-burning fuel that could help to replace fossil fuels in transportation, the chemicals industry, and many other sectors. However, hydrogen is also an explosive gas, so it is essential to have safety systems that can reliably detect leaks in a variety of circumstances.
KAUST researchers have invented a robust, highly sensitive, low-cost hydrogen sensor that outperforms commercial detectors, offering a vital safeguard for the burgeoning hydrogen economy[1].
“Conventional hydrogen sensors face several limitations,” explains Suman Mandal of the Physical Science and Engineering Division at KAUST, a member of the team behind the work. “These sensors often respond slowly to hydrogen leaks, cannot detect trace levels of hydrogen, and must be heated during operation, for example.”
The researchers have overcome these problems using a semiconducting polymer called DPP-DTT, which they coated onto a pair of platinum electrodes. Exposure to hydrogen reduced the current flowing through the device by up to 10,000 times, offering a powerful detection signal, with the drop in current corresponding to the concentration of hydrogen.
“This high responsivity ensures rapid and precise detection of gas leaks, which is essential for safety in industrial and transportation sectors,” says Mandal
The device operates at room temperature and can detect traces of hydrogen at just 192 parts per billion. It responds within one second of exposure and consumes barely two microwatts of power. Laboratory tests showed the device could operate over a wide temperature and humidity range and remained functional for two years.
The researchers tested the device in various real-world scenarios, which included hydrogen leaking from a pipe and bursting hydrogen-filled balloons in a room. They even mounted the device on a drone and flew it through an area where a hydrogen leak had occurred. In all scenarios, the device performed better than commercial sensors.
The sensor could also detect hydrogen in mixtures of volatile molecules such as ethanol and acetone, and in complex gas mixtures. The sensor only failed when the atmosphere lacked any oxygen, which provided an important clue about how it works.
Oxygen from the air enters the polymer and draws electrons from the material. This increases the current flowing through the device and leaves oxygen within the polymer and on the electrodes. If there is any hydrogen in the surrounding air, it also passes through the polymer and reaches the electrodes, where it splits into hydrogen atoms that stick to the platinum’s surface. Hydrogen and oxygen atoms then combine to form water, which escapes the device. Removing this oxygen reduces the current flowing through the device, which signals the presence of hydrogen.
“This is an entirely new hydrogen sensing mechanism,” Mandal says.
Using an inexpensive screen-printing method, the sensor could be manufactured at a low cost, making it an affordable and practical way to rapidly identify hydrogen leaks.
The team has filed a patent on the work, and plans to collaborate with a company to further develop the technology. “I believe these efforts will help address hydrogen safety issues in a cost-effective and environmentally friendly manner,” says Mandal.
Journal
Nature Electronics