The high demand for hydrogen sensors crosses over use in industrial process control and leak detection applications as well as food and medical industry, to determine the presence of various types of bacteria or underlying medical conditions.
For example in use for developing breath analyzers for non-invasive diagnosis of gastrointestinal diseases.
Inspired by the surface of butterfly wings, researchers have developed a light-activated hydrogen sensor that provides ultra-precise results at room temperature.
The technology can detect hydrogen leaks before they pose safety risks and can measure tiny amounts of the gas on people’s breath, for diagnosing gut disorders.
A prototype has been developed by researchers at RMIT University, is powered by light instead of heat. This is a phenomenal discovery as in commercial use, hydrogen sensors only work at temperatures of 150C or higher.
Fellow researcher Dr Ylias Sabri says the prototype is scalable, cost-effective and has features unmatched by any hydrogen sensors currently in the market.
“Some sensors can measure tiny amounts, others can detect larger concentrations; they all need a lot of heat to work.”
The sensor can detect hydrogen at very little concentrations, and with a broad detection range, is ideal for medical use and boosting safety in the emerging hydrogen economy.
Co- researcher Dr Ahmad Kandjani says, “Hydrogen has potential to be the fuel of the future but we know safety fears could affect public confidence in this renewable energy source.”
“By delivering precise and reliable sensing technology that can detect the tiniest of leaks, well before they become dangerous, the technology can transform energy supplies the world over.”
Butterfly bumps: how the sensor works
The innovative core of the new sensor is made up of tiny spheres known as photonic or colloidal crystals.
The hollow shapes, similar to the bumps found on butterfly wings, are highly ordered structures that are very efficient at absorbing light. This allows it to draw all the energy it needs to operate from a beam of light rather than heat.
The modelled photonic crystals enable the sensor to be activated by light and have the structural consistency for reliable gas sensing.
To make the sensor an electronic chip is covered with a thin layer of photonic crystals and also with titanium palladium composite.
When hydrogen interacts with the chip, the gas is converted to water. This process creates an electronic current and by measuring the magnitude of the current, the sensor can tell precisely how much hydrogen is present.
Unlike many commercial sensors, the new technology is highly selective and can accurately isolate hydrogen from other gases.
Elevated levels of hydrogen is known to be connected to gastrointestinal disorders, making the technology very important for use in medical diagnosis and monitoring.
The standard approach is through breath samples, sent to labs for processing. The new chip can be integrated into hand-held device to deliver instant results.
Dr Ylias Sabri says, “With gut conditions, the difference between healthy levels of hydrogen and unhealthy levels is miniscule. But our sensor can accurately measure such tiny differences.”
A provisional patent application has been filed for the technology and the research team hopes to collaborate with manufacturers of hydrogen sensors, fuel cells, batteries or medical diagnostic companies to commercialise the sensor.
The gas sensing investigation has been in the making for over two decades led by RMIT’s Centre for Advanced Materials and Industrial Chemistry (CAMIC).