S'pore team finds cheaper way to print light sheets

SINGAPORE - The technology may not be new but a team of Singapore researchers has managed to harness the ability to produce flexible sheets of light in a big and affordable way.

And if all goes well, it could soon light up prominent buildings near City Hall or make an appearance in large-scale parades here.

Called "printed light", the phosphor-based technology comes in the form of 50 sq m sheets that glow when connected to electricity sources.

"It can be used to light large building facades or make huge outdoor billboards," said researcher Lok Boon Keng from the Singapore Institute of Manufacturing Technology (SIMTech).

Printed light technology has existed in its raw form since the 1990s. But until a year ago, manufacturers could print them only in about 1 sq m sheets.

"As size increases, complexity of printing increases too."

But Mr Lok and his team found a way to print these light sheets the way newspapers are printed - in large rolls - thus reducing costs by up to 30 per cent.

"We hope it can help light up Times Square or even the skyline around the Bund in Shanghai.

"Our dream is to have a piece of Singapore in these places."

Printed light consists of several layers of material including transparent electrodes, a phosphor- based layer that lights up, and a ceramic-based insulator.

A special printer deposits these layers onto a film that forms the base of printed light sheets. The next step involves the mounting of a graphic layer, such as an advertisement, on top of these sheets to form a lighted billboard.

Users just need to connect it to an electricity source, switch it on and watch it illuminate.

Such large-scale printed lighting has already piqued the interest of building owners, green materials manufacturers and even costume designers.

For example, printed lighting was used in signages and works of art at a recent sustainable light art festival, i Light Marina Bay.

Green Building Group, a green materials manufacturer, is placing its bets on the technology, having licensed it from SIMTech.

Printed light consumes considerably less power at about 60 watts per sq m, compared to LED screens which can consume 1,200 watts per sq m, said the group's managing director Philip Kwang.

"Think of LED screens as sunlight - you can't stare at them for too long. But printed light is like moonlight, it's less bright and more soothing," he added.

The group is in discussions with building owners around City Hall to use printed light for their facades. Events firm Cityneon is in talks with organisers of large- scale local parades to use this flexible lighting material in costumes.

The cost of printed light is comparable to LED screens, which costs more than $20,000 for 100 sq m, said Mr Lok. But printed light can feature only static images while LED screens can show moving ones.

"It might take five more years to introduce moving pictures to printed light... That's something that we want to work on."

kashc@sph.com.sg

This article was published on April 7 in The Straits Times.

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