There is extremely high demand for hydrogen gas (H2) sensors in industrial sectors such as the food, leak detection, medical and process control fields. Yet, the problem has always been a lack of available sensors that possess extremely high sensitivity and a low limit of detection (LoD) with regards to hydrogen.
Now, a new light-activated sensor has been developed that draws inspiration from the surface of butterfly wings and can detect hydrogen leaks accurately at room temperature. Detection occurs before the leaks become a risk to the safety of nearby people, and the sensors can also detect miniscule traces of gas on one’s breath, which is a symptom of gut disorders.
Existing hydrogen sensor technology works well at 150° C and above, but the innovative team at RMIT University in Melbourne, Australia, has come up with a new concept that does not have such restrictions. The sensor technology is powered by light instead of heat, and mimics the bumpy surface found on butterfly wings, made up of microstructures that give it its unique texture.
New sensor technology mimics the surface of butterfly wings. Source: blackdiamond67/Adobe Stock
This creation is scalable, offers a full package of features and is also cost-effective, according to the co-lead researcher Dr. Ylias Sabri. The range of features that this particular sensor offers cannot be matched by anything currently on the market. Some models are adept at measuring very little amounts, others can measure larger concentrations of hydrogen. However, the catch is that they all need quite a lot of heat to operate properly.
The team at RMIT claims that this new hydrogen sensor can serve all purposes. They state that it can work at room temperature, and that it is selective, sensitive and can detect hydrogen accurately across a wide range of quantities.
Why is this important?
The sensor is appropriate for use in the “hydrogen economy,” promising to be the fuel of the future, and in the medical sector. However, there are many safety concerns around the widespread use of hydrogen, and that is where this new sensor can help.
The sensor can be a safety net for detecting hydrogen leaks reliably and accurately, even at minute levels, to prevent dangerous situations. Hydrogen can be an asphyxiant in substantial quantities, and can also explode with great force if ignited. By reducing the fear around hydrogen power, this sensor alone could revolutionize the hydrogen economy, and aim for a greener future.
How does it work?
Photonic (or colloidal) crystals are what makes up the core of the new sensor. These tiny spheres are hollow and are very similar to the bumps that make butterfly wings rough. They are also very efficient at absorbing light, which enables the sensor to take power from a beam of light, rather than an abundance of heat.
A sensor that is cheaper to run than the conventional hydrogen sensors that run at 150° C is a by-product of this efficiency, and the photonic crystals generate the perfect structure that accurate gas sensing requires. A sensor with consistent fabrication quality and a consistent structure is one that will give consistent results.
Due to these bio-inspired spheres, and a well-rounded and developed fabrication process, the sensors and technology behind them are easily scalable to industrial levels. This means that hundreds (if not thousands) of these sensors could be made at a rapid pace, making them viable for widespread use and ideal for the global market.
How are they made?
Electronic chips are coated in a relatively thin layer of the photonic crystals, and next a layer of titanium palladium composite. When the chips come into contact with hydrogen, it converts the gas into water. This conversion produces an electric current and the magnitude of this is measured to determine the amount of hydrogen that is present.
Contrary to the existing sensors on the market, this technology can accurately differentiate between hydrogen and other gases. It is highly selective and will not struggle in the presence of nitrous oxide, unlike its competitors.
Applications
High levels of hydrogen detected in a person's breath could signal gastrointestinal problems. As such, these sensors can also be used in the medical field to monitor and diagnose gastrointestinal issues. Currently, a breath sample must be taken and then sent to a laboratory for testing and processing.
One of the many applications of this new sensor is diagnosing gastrointestinal problems. Source: motortion/Adobe Stock
This could all change with the development of a sensor that could be integrated into a portable hand-held device that can produce real-time results.
The margin for error in the medical field is typically very low, and this application is no exception. The difference between healthy levels of hydrogen and unhealthy levels is around 10 parts per million, which is virtually undetectable. Conversely, the amount of hydrogen that needs to be present for an explosion is about 40,000 parts per million. However, the new sensor is up to the task and can measure precisely at both levels.
A provisional patent has been filed for this new creation and the aim is to work with established hydrogen sensor, battery and fuel cell manufacturers to bring the product to life and distribute it as quickly as possible.
Have thoughts about this new sensor or experience in this field? Let Electronics360 know in the comments below.
