Hydrogen sensor with record ultra-low-power consumption

In the framework of Holst Centre, IMEC and Nanosens have developed an ultra-low-power hydrogen sensor based on palladium nanowires. It shows a reproducible response to hydrogen concentrations as low as 2.7ppm, while consuming a mere 1nW power. Sensors such as these can be used, for example, in fuel cells or to monitor for gas leaks.

Palladium is known as one of the best materials for hydrogen sensing, as it is able to absorb up to 600 times its own volume of hydrogen. In the presence of hydrogen, palladium forms the more resistive palladium-hydride. Such resistive sensor elements are of particular interest as they enable relatively straightforward signal detection and fabrication. For the palladium-based sensors that are currently available, the response times and sensitivity are insufficient; but more importantly, these sensors do not meet the ultra-low-power requirements for integration with wireless autonomous sensor nodes needed in many applications.

Nanosens, a Dutch company developing innovative nanotech solutions, has invented CMOS compatible processes to fabricate highly uniform, long, and small nanowires of various materials, including palladium.

At Holst Centre, chips with palladium nanowires have been subjected to a wide range of hydrogen concentrations in nitrogen. The sensor shows a reversible response to hydrogen concentrations as low as 2.7ppm while consuming a mere 1nW of power. To the best of our knowledge this is the hydrogen sensor with the lowest power consumption to date. Additionally, the sensor response to hydrogen is highly reproducible and stable over a period of up to six months. In a next step, a low-power read-out circuitry will be developed at Holst Centre. This will result in a full sensing device.

Hydrogen is widely used in many industries. It is also touted to become one of the main energy carriers of the future, replacing fossil fuels. Hydrogen sensors thus represent an important opportunity. They could be used in applications as varied as detecting impending electrical power transformer failure, or monitoring hydrogen concentrations in fuel cells. And for all hydrogen-based industrial applications, the availability of sensitive and effective hydrogen sensors to quickly respond to hydrogen gas leaks and to monitor manufacturing and distribution is paramount.