Since the invention of the optical microscope in the 17th century, scientists and doctors have used it to magnify and study tissues, cells and micro-organisms that cannot be seen with our naked eye. However, microscopes can only show objects down to 200 nm in size, which means there are many objects too small to be seen.
One example is viruses. Coronaviruses, the cause of viral outbreaks like the severe acute respiratory syndrome (SARS), measure between 100 and 140 nanometres in diameter
Scientists can use microscopy techniques to push the boundaries of a regular microscope, such as treating samples with fluorescent molecules to enhance the imaging. However, these invasive methods are less than ideal as they can modify biological specimens in the process.
An invention from researchers at National University of Singapore’s Department of Electrical and Computer Engineering has made it easy and cost efficient to upgrade microscopes to nanoscopes using just miniature glass spheres. An added bonus – it can even image live biological specimens under natural light without damaging or harming the specimens.
Images taken by the nanoscope; size of the nano-flower is one micrometre and the line width is 50 nm (Credit: Professor Hong Minghui)
Professor Hong Minghui, one of the lead researchers, shared that the miniature glass spheres – known as microspheres – acting like tiny magnifying glasses to enhance the resolution of a microscope by 10 times.
The interaction between the microspheres and the specimens is then captured by an optical detector. Piecing together the images from the separate microspheres to create an enhanced and zoomed-in image of the specimen can provide scientists with greater insight, beyond what a regular microscope is capable of.
In fact, this invention set a new world record for optical microscopy technology in 2016, by showing precise details of specimens that are only 23 nanometres in length.
By modifying regular microscopes, this invention also means that the resulting nanoscope is easy to operate and does not require special user training. It can be used by science teachers in schools, inspection workers in chemical and electronic factories, doctors and nurses for early diagnosis of viral outbreaks, as well as for scientific research in laboratories.
The patented design has been recognized in Singapore and internationally, having received the Prestigious Engineering Achievement Award 2016 from the Institution of Engineers Singapore, and the Outstanding Engineering Achievement Award 2016 by the Association of Southeast Asian Nations.
This invention was initially supported by National Research Foundation Singapore under the Competitive Research Programme, which supports use-inspired basic research.
Spurred by a belief that technological innovation should be used to improve people’s lives, Professor Hong went on to commercialize the technology through a spin-off company called Phaos Technology Pte Ltd – which means “light” in Greek.
Professor Hong (centre) and the team showing the prototype at InnovFest unBound 2017. (Credit: Professor Hong Ming Hui)
Phaos Technology has received positive response with orders since it was established in March 2017. Companies in microelectronics, biomedicine and education have also expressed interests in research collaborations and technology commercialisation. Phaos is expected to increase its orders to 100s optical nanoscopes in 3 years and occupy one piece of market share in optical imaging in the world.