Showing posts with label Alessandro Tuniz. Show all posts
Showing posts with label Alessandro Tuniz. Show all posts

Friday, December 27, 2013

A new way of seeing: Metamaterial lens has ten times more power


http://www.thealmagest.com/new-way-seeing-metamaterial-lens-ten-times-power-2/8427

A lens with ten times the resolution of any current lens, making it a powerful new tool for the biological sciences has been developed by researchers at the University of Sydney.
“This advance means we can unlock previously inaccessible information on the structure of molecules, their chemical make-up and the presence of certain proteins,” said Alessandro Tuniz, lead author of an article on the lens published in Nature Communications.
Tuniz, a postdoctoral associate at the University, said, “This opens up an entirely new tool for biological studies. It could allow earlier skin cancer diagnosis, because smaller melanomas can be recognised. For breast cancer, it can also be used to more accurately check that all traces of a tumour have been cut out during surgery.”
The four member research team from the University’s School of Physics, including Alessandro Tuniz, are all authors on the paper. They created the lens using fibre optic manufacturing technology.
The lens is a metamaterial – a material with completely new properties not found in nature.
Making the lens was not a matter of making a better form of the lenses already in existence but of making a lens which uses light waves in a way not previously possible.
“Creating metamaterials is a cutting-edge area of science with a massive range of potential uses from aerospace to solar power, telecommunications to defence,” said researcher Dr Boris Kuhlmey.
“The major challenge is making these materials on a scale that is useful. This is one of the first times a metamaterial with a real world application, quickly able to be realised, has been feasible. Within the next two to three years, new terahertz microscopes that are ten times more powerful than current ones will be possible using our metamaterial.
“We know of only two or three other cases worldwide, including for wireless internet and MRI applications, where metamaterials could also be put into practice in the next couple of years.”
The potential to create a new high power lens, able to see much finer details than using conventional lenses was spotted almost a decade ago. It has taken until now to make the lens on a useful scale, a thousand times smaller than the early experimental models.
“The difficulty was making large quantities of matter structured on a micrometric scale,” said Alessandro Tuniz.
The new lens, made of plastic and metal, uses terahertz waves, electromagnetic waves with frequencies higher than microwaves but lower than infrared radiation and visible light. It operates in a region of the spectrum where very few other optical tools are available and all of them have limitations, in particular in terms of resolution.
“If we think of this in comparison to an X-ray which allows us to see inside objects at a high resolution but with associated danger from radiation, by contrast our metamaterial lens allows us not only to see through some opaque materials, but also to gather information on their chemical composition, and even information on interaction between certain molecules, without the danger of X-rays,” Tuniz said.

Tuesday, October 29, 2013

More on the University of Sydney microscopes: Metamaterial lens promises clinical diagnoses


http://optics.org/news/4/10/51
Terahertz device produced by University of Sydney team could lead to new microscopes 'within two or three years'.
Sydney team
Sydney team
A research team in Australia says that a new type of lens based on metamaterials could open up an entirely new field of medical diagnostics within just three years.
Critically, the device is far smaller than any previous attempts at making metamaterial lenses, and was produced using the industrial method of fiber drawing – suggesting that it has a good chance of transitioning to commercial use.
The University of Sydney group, whose work has just been published in the journal Nature Communications, says that the lens, which operates in the terahertz spectral region, could be used for early cancer diagnosis or to monitor drug delivery to cells.
According to lead author Alessandro Tuniz and his colleagues at Sydney, the lens has ten times the resolution of any current equivalent, making it a potentially very powerful tool for biological sciences and medicine.
In a release accompanying the paper’s publication, Tuniz explained: “This advance means we can unlock previously inaccessible information on the structure of molecules, their chemical make-up and the presence of certain proteins.”
“This opens up an entirely new tool for biological studies,” he predicted. “It could allow earlier skin cancer diagnosis, because smaller melanomas can be recognized. For breast cancer, it can also be used to more accurately check that all traces of a tumor have been cut out during surgery.”
Industrial-style production
Based on a combination of metal and plastic materials, the lens operates in the terahertz region – situated between the far-infrared and microwave regions of the electromagnetic spectrum. That should enable physicians to see phenomena that until now have been invisible.
The lens was made using the well-known fiber-drawing method, and based on a stack of more than 450 tapered indium wires arranged hexagonally and surrounded by a polymer with a high terahertz transmission.
In focus: the Sydney team's lens
In focus: the Sydney team's lens
The stack of indium wires was then heated and drawn to produce a fiber containing a long, continuous array of metal microwires that can be chopped into a large number of smaller devices – indicating the method's scalability.
“The wire-based hyperlenses we demonstrate here are three orders of magnitude smaller than previous experiments in the microwave,” writes the team in its paper.
Manufacturing challenge
While metamaterials has become a key new area of photonics research, the difficulty of making technologically useful devices has, until now, restricted any potential industrial impact.
Boris Kuhlmey from the Sydney team commented: “We know of only two or three other cases worldwide, including for wireless internet and MRI applications, where metamaterials could also be put into practice in the next couple of years.”
He explains that a key challenge has been to make metamaterials on a useful scale. “This is one of the first times a metamaterial with a real-world application, quickly able to be realized, has been feasible,” Kuhlmey said.
“Within the next two to three years, new terahertz microscopes that are ten times more powerful than current ones will be possible using our metamaterial.”
Beating the optical diffraction limit
In their paper, the Sydney researchers describe their adoption of wire array metamaterials as the key to the breakthrough. Because of their extreme anisotropy, they are able to beat the conventional diffraction limit that typically restricts optical microscopy techniques to a resolution of half the wavelength of light being used to interrogate a specimen.
But until now they had only been demonstrated at microwave frequencies, and even then were restricted to extremely short propagation lengths that would not be clinically useful.
In the abstract of the paper, Tuniz and colleagues write: “We demonstrate imaging through straight and tapered wire arrays operating in the terahertz spectrum, with unprecedented propagation of near-field information over hundreds of wavelengths and focusing down to 1/28 of the wavelength with a net increase in power density.”
“Applications could include in vivo terahertz endoscopes with resolution compatible with imaging individual cells."
Although some existing techniques are already able to beat the optical diffraction limit, they are typically complex and expensive in nature, and their use has so far been restricted to central technology development laboratories rather than clinical application.
Tuniz also highlights the potential spectroscopic usefulness of terahertz technology beyond that of conventional X-ray imaging, saying: “The metamaterial lens would allow us not only to see through some opaque materials, but also to gather information on their chemical composition, and even information on interaction between certain molecules, without the danger of X-rays.”
That could result in the lens being used to analyze the delivery of drugs to individual cells, something that may prove revolutionary in future medical research.

Abstract-Metamaterial fibres for subdiffraction imaging and focusing at terahertz frequencies over optically long distances




  • Using conventional materials, the resolution of focusing and imaging devices is limited by diffraction to about half the wavelength of light, as high spatial frequencies do not propagate in isotropic materials. Wire array metamaterials, because of their extreme anisotropy, can beat this limit; however, focusing with these has only been demonstrated up to microwave frequencies and using propagation over a few wavelengths only. Here we show that the principle can be scaled to frequencies orders of magnitudes higher and to considerably longer propagation lengths. We demonstrate imaging through straight and tapered wire arrays operating in the terahertz spectrum, with unprecedented propagation of near field information over hundreds of wavelengths and focusing down to 1/28 of the wavelength with a net increase in power density. Applications could include in vivo terahertz-endoscopes with resolution compatible with imaging individual cells.

  • A new way of seeing - meta-material lens with ten times more power


    http://sydney.edu.au/news/physics/1737.html?newsstoryid=12568

    School of Physics researchers have developed a meta-material lens with ten times the resolution of any current lens, making it a powerful new tool for the biological sciences. The results were published in Nature Communications on October 29 2013
    Dr Alessandro Tuniz and his team have developed a meta-material lens, a powerful tool for biological science.
    Dr Alessandro Tuniz and his team have developed a meta-material lens, a powerful tool for biological science.
    "This advance means we can unlock previously inaccessible information on the structure of molecules, their chemical make-up and the presence of certain proteins," said lead author Dr Alessandro Tuniz.
    Dr Tuniz, a postdoctoral associate at the University, said, "This opens up an entirely new tool for biological studies. It could allow earlier skin cancer diagnosis, because smaller melanomas can be recognised. For breast cancer, it can also be used to more accurately check that all traces of a tumour have been cut out during surgery."
    The four member research team from the University's School of Physics, including Alessandro Tuniz, are all authors on the paper. They created the lens using fibre optic manufacturing technology.
    The lens is a metamaterial - a material with completely new properties not found in nature.
    The meta-material fibre consisting of a long continuous array of metal microwires
    The meta-material fibre consisting of a long continuous array of metal microwires
    Making the lens was not a matter of making a better form of the lenses already in existence but of making a lens which uses light waves in a way not previously possible.
    "Creating metamaterials is a cutting-edge area of science with a massive range of potential uses from aerospace to solar power, telecommunications to defence," said team member Dr Boris Kuhlmey.
    "The major challenge is making these materials on a scale that is useful. This is one of the first times a metamaterial with a real world application, quickly able to be realised, has been feasible. Within the next two to three years, new terahertz microscopes that are ten times more powerful than current ones will be possible using our metamaterial.
    "We know of only two or three other cases worldwide, including for wireless internet and MRI applications, where metamaterials could also be put into practice in the next couple of years."
    The potential to create a new high power lens, able to see much finer details than using conventional lenses was spotted almost a decade ago. It has taken until now to make the lens on a useful scale, a thousand times smaller than the early experimental models.
    "The difficulty was making large quantities of matter structured on a micrometric scale," said Dr Tuniz.
    The new lens, made of plastic and metal, uses terahertz waves, electromagnetic waves with frequencies higher than microwaves but lower than infrared radiation and visible light. It operates in a region of the spectrum where very few other optical tools are available and all of them have limitations, in particular in terms of resolution.
    "If we think of this in comparison to an X-ray which allows us to see inside objects at a high resolution but with associated danger from radiation, by contrast our metamaterial lens allows us not only to see through some opaque materials, but also to gather information on their chemical composition, and even information on interaction between certain molecules, without the danger of X-rays," said Dr Tuniz.
    This means the lens is perfectly suited to analysing the delivery of drugs to cells, which is crucial to medical research.
    This research was undertaken with the Freiburg Materials Research Centre from the University of Freiburg and supported by the Australian Research Council, and the Australian National Fabrication Facility using commonwealth and NSW state government funding.

    Read the article published in Nature Communications here

    Contact: Tom Gordon
    Phone: 02 93513201