"The technology we are working on could transform water sanitation techniques and offer access to clean drinking water even to remote developing regions via portable systems," says Christian Zollner of the University of California at Santa Barbara.
Zollner worked on light-emitting diodes (LEDs), the long-lasting technology in modern light bulbs. They are probably in the bulbs of your home or in the headlights of your car.
Because they are tough and energy efficient, researchers are always trying to find new ways to use them.
Zollner and his team worked on LEDs that emit ultraviolet light, particularly UV-C light, which is deadly for bacteria and viruses, including coronavirus.
His goal is to make those LEDs more powerful, robust and cheaper.
"At the moment, UV LEDs are capable of delivering a few milliwatts of power. Our goal is to make them 10 to 20 times more powerful.
"Previously our goal was mainly to use them for water sterilization, but the Covid-19 pandemic made us understand that there is also a large market for the sanitation of surfaces and equipment. If there is another viral situation in about five or ten years, this technology could be very useful. "
At the moment its lights are powerful enough to clean a closed closet, but they must be 20 times more powerful to hoe an entire room.
Light can also damage human skin and eyes, so commercial applications are limited.
But a company has found a use. The Californian company LARQ produces the first self-cleaning water bottle in the world.
His solution to prevent exposure to UV-C light is to ensure that the small UV LEDs in the lids of his bottles only light up when the bottles are screwed on.
Users then need to push the lid down to activate the technology, which according to the company more or less eradicates all bacteria and viruses in 60 seconds.
LEDs have come a long way since the first ones were produced in the 1960s.
Back then, the only light that semiconductor devices could generate was an infrared light invisible to the human eye.
Now, they cover the entire visible spectrum, as well as infrared and UV light and are available in an extraordinary range of shapes.
Micro-LEDs measuring less than 1mm in diameter are another of the latest variations.
Designed for use in high-end screens, micro-LEDs promise blacks more blacks, brighter blues.
Samsung has shown its huge micro-LED screen at consumer electronics shows.
"Micro-LED display technology offers a huge improvement to standard LED panels due to its optimal brightness and image definition," says Damon Crowhurst, Samsung UK display manager.
But the engineering involved is staggering. The screens need millions of micro-LEDs, which means they are expensive: a 75-inch TV costs tens of thousands of pounds.
"Micro-LED screens cost around £ 1,000 per inch, so a 75-inch micro-LED TV could easily cost the same as a new Porsche Cayenne," says Paul Gray, an analyst with global technology researcher Omdia.
"You have to ask yourself how many people are willing to pay to get better contrast when they watch TV."
The extremely high cost of micro-LEDs is one of the reasons why some manufacturers currently prefer mini-LEDs, which although they are still tiny over 1mm in diameter.
Apple, for example, is said to be developing six new products with mini-LED displays, including iPads and MacBooks.
In the short term, small-screen devices such as smartwatches are expected to represent the largest growth area for micro-LEDs.
"Small screens are a much simpler proposition, as a 1 cm micro-LED screen can be made on a single silicon chip," says Gray.
"They are already used in camera viewfinders. So for products like smartwatches we are looking at a much shorter time frame."
Researchers are finding increasingly exotic ways to make the perfect LED: more light with less energy.
British start-up Kubos Semiconductors is developing LEDs based on a form of gallium nitride (GaN) with a cubic rather than hexagonal crystalline structure, an approach that it believes can solve long-term problems by creating more efficient micro-LEDs.
Currently, green and amber LEDs are up to three times less efficient than blue and red ones.
Known as Green Gap, the phenomenon reduces performance and increases the cost of lighting and displays.
"This will be very important in applications such as cell phones and smartwatches where displays need to drain the battery," says Caroline O'Brien, CEO of Kubos.
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Elsewhere, researchers are working to reduce LED production costs and environmental impact.
An EU-funded study is pioneering the use of naturally occurring fluorescent protein structures to create bio-LEDs.
Based in Austria, Spain and Italy, the multi-university project started in January and is expected to last four years.
"The goal is to find a cheaper and greener way of producing LEDs while avoiding the need for inorganic phosphates that need to be extracted in specific places," says Gustav Oberdorfer, who is conducting research at the Graz University of Technology in Austria.
"We hope that our LEDs will be used commercially in devices within the next 10 years and we believe they could both reduce the cost of LED devices and make them much more sustainable."
So the next time you turn on a light, think of the humble LED, which has come a long way since the 1960s and has a bright future.
