Australasian Science: Australia's authority on science since 1938

Nanotech Makes Glass Smart

Australian researchers have developed a method for embedding light-emitting nanoparticles into glass without losing any of their unique properties.

The “hybrid glass” successfully combines these special luminescent nanoparticles with the useful properties of glass, such as transparency and the ability to be processed into fine optical fibres – a major step towards the development of 3D display screens and remote radiation sensors.

“These novel luminescent nanoparticles, called upconversion nanoparticles, have become promising candidates for a whole variety of ultra-high-tech applications such as biological sensing, biomedical imaging and 3D volumetric displays,” says lead author Dr Tim Zhao of The University of Adelaide.

“Integrating these nanoparticles into glass, which is usually inert, opens up exciting possibilities for new hybrid materials and devices that can take advantage of the properties of nanoparticles in ways we haven’t been able to do before.

“For example, neuroscientists currently use dye injected into the brain and lasers to be able to guide a glass pipette to the site they are interested in. If fluorescent nanoparticles were embedded in the glass pipettes, the unique luminescence of the hybrid glass could act like a torch to guide the pipette directly to the individual neurons of interest.”

The researchers believe their “direct doping” approach can be generalised to other nanoparticles with interesting photonic, electronic and magnetic properties. The applications will depend on the properties of the nanoparticle. “If we infuse glass with a nanoparticle that is sensitive to radiation and then draw that hybrid glass into a fibre, we could have a remote sensor suitable for nuclear facilities,” Zhao says.

To date, the method used to integrate upconversion nano­particles into glass has relied on the in situ growth of the nanoparticles within the glass. “We’ve seen remarkable progress in this area, but the control over the nanoparticles and the glass compositions has been limited, restricting the development of many proposed applications,” says project leader Prof Heike Ebendorff-Heideprem.

“With our new direct doping method, which involves synthesising the nanoparticles and glass separately and then combining them using the right conditions, we’ve been able to keep the nanoparticles intact and well dispersed throughout the glass. The nanoparticles remain functional and the glass transparency is still very close to its original quality.

The research has been published in Advanced Optical Materials (http://tinyurl.com/zkcre53).