The nifty nanoparticles help ‘open the curtain’ to the world of super-small things
(Nanowerk News) Physicists at the Australian National University (ANU) are using nanoparticles to develop a new light source that will allow us to “pull the curtain” onto the world of minuscule objects – thousands of times smaller than a human hair – with huge advantages for medical and other technologies.
The findings, published in Science Advances (“Generation of high harmonics from dielectric resonators with long wavelengths”), could have major implications for medical science by offering an affordable and effective solution for analyzing tiny objects too small to be seen by a microscope, let alone the human eye. This work could also benefit the semiconductor industry and improve quality control of computer chip manufacturing.
ANU technology uses carefully engineered nanoparticles to increase the frequency of light that cameras and other technologies see by up to seven times. The researchers say there is “no limit” to how high the frequency of light can be increased. The higher the frequency, the smaller the objects we can see using the light source.
The technology, which only requires a single nanoparticle to work, can be implemented into microscopes to help scientists magnify the world of supersmall objects with a resolution 10 times that of conventional microscopes. This will allow researchers to study objects that are too small to see, such as the inner structure of cells and individual viruses.
Being able to analyze such small objects could help scientists better understand and fight certain diseases and health conditions.
“Conventional microscopes are only capable of studying objects larger than about a ten-millionth of a meter. However, there is increasing demand in various sectors, including the medical field, to be able to analyze much smaller objects down to a billionth of a meter,” lead author Dr Anastasiia Zalogina, from the ANU Research School of Physics and the University of Adelaide, said.
“Our technology can help meet that demand.”
Researchers say the nanotechnology developed by ANU could help create a new generation of microscopes that can produce much more detailed images.
“Scientists who want to produce magnified images of very small nanoscale objects cannot use conventional optical microscopes. Instead, they have to rely on high-resolution microscopy techniques or use electron microscopy to study these tiny objects,” said Dr Zalogina.
“But such techniques are slow and the technology is very expensive, often costing over a million dollars.
“Another disadvantage of electron microscopy is that it can damage the delicate sample being analyzed, whereas light-based microscopy reduces this problem.”
The beams of light that we think of as different colors of the rainbow are oscillating electromagnetic waves with different frequencies.
What we see as red is the lowest frequency our eyes can detect. Even the lower frequencies that are invisible to the human eye are called infrared. Violet has the highest frequency of light that we can see. Ultraviolet, which has a higher frequency, is invisible to the human eye.
Although our eyes cannot detect infrared and ultraviolet light, we can ‘see’ them using cameras and other technology.
Co-author Dr Sergey Kruk, also from ANU, said the researchers were interested in reaching very high frequencies of light, also known as ‘extreme ultraviolet’.
“With purple light we can see much smaller objects compared to using red light. And with an ultra-ultraviolet light source we can see things that are beyond what is possible using today’s conventional microscopes,” said Dr Kruk.
Dr Kruk said ANU’s technology could also be used in the semiconductor industry as a quality control measure to ensure efficient production processes.
“Computer chips are made up of very small components with feature sizes nearly as small as a billionth of a meter. During the chip production process, it is beneficial for manufacturers to use a small source of ultra-ultraviolet light to monitor this process in real-time to diagnose problems early on,” he said.
“That way manufacturers can save resources and time on bad chip batches, increasing chip output. It is estimated that a one percent increase in computer chip manufacturing output translates to a two billion dollar savings.
“Australia’s fast-growing optical and photonics industry is represented by nearly 500 companies and accounts for around $4.3 billion of economic activity, making our high-tech ecosystem well-positioned to adopt new types of light sources to reach new global markets in nanotechnology research and industry. . .”
This work was carried out in collaboration with researchers from the University of Brescia, University of Arizona and Korea University.