The "lab-on-a-chip" of optical analysis has opened the door to the widespread use of portable spectrometers

Scientists, including Oregon State University materials researchers, have developed a better light-measuring tool that contributes to the field of optical spectroscopy, from smartphone cameras to environmental monitoring, which could improve everything
from smartphone cameras.

The research, published today in the journal Science and led by Aalto University in Finland, has resulted in a powerful ultra-tiny spectrometer that can be mounted on a microchip and operated
using artificial intelligence.

The research involved a relatively new ultra-thin material called a two-dimensional semiconductor, and the results proved the concept of a spectrometer that could be easily integrated into a variety of technologies, including quality inspection platforms, safety sensors, biomedical analyzers, and space telescopes
.

"We showed a way to build a spectrometer that was much smaller than the spectrometers typically used today," said
Ethan Minot, a professor of physics in the College of Science at Oregon State University.
"Spectrometers, which measure the intensity of light at different wavelengths, are very useful in many industries and in all areas of science to identify samples and characterize materials
.
"

While traditional spectrometers require bulky optical and mechanical components, the new device can be mounted on the ends of a person's hair, Minot said
.
The new study shows that these components can be replaced with new semiconductor materials and artificial intelligence, significantly reducing
the size of the spectrometer from the smallest spectrometer today.

"Our spectrometer does not require assembling separate optical and mechanical components or array designs to disperse and filter light," said Hoon Hahn Yoon, who led the study
with Aalto University colleague Zhipei Sun Yoon.
"In addition, it can achieve high resolution comparable to benchtop systems, but in a much smaller
volume.
"

The researchers say the device is 100 percent electrically controlled for the color of the light it absorbs, giving it the potential
for huge scalability and wide availability.

Professor Yoon said: "Integrating it directly into portable devices such as smartphones and drones can improve our daily lives
.
Imagine that our next generation of smartphone cameras could be hyperspectral cameras
.
”

These hyperspectral cameras can not only capture and analyze information from the visible light band, but also perform infrared imaging and analysis
.

Minot said: "It is exciting that our spectrometers offer the possibility
of a variety of new everyday equipment and instruments.
"

In medicine, for example, spectrometers are already testing their ability to recognize subtle changes in human tissue, such as the difference between
tumors and healthy tissue.

For environmental monitoring, Minot adds, spectrometers can accurately detect the types of pollution in the air, water or ground, as well as the amount
of pollutants.

"It would be great if there were low-cost portable spectrometers to do the work for us," he said
.
"In an educational setting, the practical teaching of scientific concepts will be more effective
with cheap, compact spectrometers.
"

Minot says there are also plenty
of apps for science-oriented enthusiasts.

"If you like astronomy, you might be interested in measuring spectra collected with telescopes and using that information to identify stars or planets
," he said.
"If your hobby is geology, you can identify gemstones
by measuring the spectrum they absorb.
"

Minot believes that as research on 2D semiconductors progresses, "we will quickly discover new ways to
take advantage of their novel optical and electronic properties.
" "Starting from graphene, the research on two-dimensional semiconductors has only been carried out for more than ten years
.
Graphene is a type of carbon arranged in a honeycomb lattice with a thickness of only one atom.

"It's really exciting," Minot said
.
"I believe that by studying two-dimensional semiconductors, we will continue to make interesting breakthroughs
.
"

In addition to Minot, Yoon and Sun, the collaboration includes scientists from Shanghai Jiao Tong University, Zhejiang University, Sichuan University, Yonsei University and Cambridge University, as well as other researchers
from Aalto University.