Atoms assembled in new way
Australian researchers have come up with a high-tech way to assemble single nanoparticles for futuristic devices.
Smart phones, tablets and laptop displays, camera lenses, biosensing devices, integrated chips and solar photovoltaic cells could all benefit from the innovative method of nanocrystal assembly.
Normally, nanocrystals are made with wet chemical methods that present challenges when seeking to incorporate them effectively into devices.
But the new method allows single nanoparticles to be placed directly into a pre-patterned template.
The technique is called electrophoretic deposition (EPD), and has been used by researchers at the University of Melbourne and CSIRO to create a nearly perfect single nanocrystal array using either gold nanospheres or gold nanorods.
By tweaking the potential applied to the materials as part of this field, the researchers discovered they were even able to dictate whether the nanocrystals assemble in vertical or horizontal configurations.
With the ability to assemble in both vertical and horizontal directions and with spatial control of the nanoparticles on the surface, the method provides far more opportunities to build and manufacture nanoscale structures.
It is a new approach to large scale fabrication for nanomaterials, solving a fundamental roadblock for nanotechnology and creating a new pathway for miniaturisation of both optical and electronic devices.
The technique has already been applied to semiconductor quantum dots, magnetic nanoparticles and organic nanoparticles, gaining significant attention from potential industry partners.
“We can use assembled gold nanocrystals arrays as a plasmonic pixel, which is a colour display unit with high purity and colour saturation,” lead author Heyou Zhang said.
“It provides very distinct colour with angle or polarization-dependent properties, which has potential as a security feature or in medical imaging.
“We can use these particles to build up reconfigurable metal lenses, such as the lenses on your phone.
“The thickness of the lens on your phone camera is limited by optical geometries, but with this method you might be able to shrink it down to micrometre size.”
The research team is now looking for partners to help scale-up the novel EPD process.