Tiny Spectrometer Shows Comparable Resolution to Benchtop Instruments

A new technique for measuring light is enabling a powerful, ultra-tiny spectrometer that fits on a microchip and could be used in a plethora of applications, including biomedical analyzers.  The research—led by Finland’s Aalto University with participation from materials researchers at Oregon State University (OSU)—involved a comparatively new class of super-thin materials known as two-dimensional semiconductors.

“Spectrometers measure the strength of light at different wavelengths and are super useful in lots of industries and all fields of science for identifying samples and characterizing materials,” said Ethan Minot, a professor of physics in the OSU College of Science. “We’ve demonstrated a way of building spectrometers that are far more miniature than what is typically used today.”  

Traditional spectrometers require bulky optical and mechanical components, whereas the new device could fit on the end of a human hair, Minot said. The research—published recently in Science—suggests those components can be replaced with novel semiconductor materials and AI, allowing spectrometers to be dramatically scaled down in size from the current smallest ones, which are about the size of a grape.

“Our spectrometer does not require assembling separate optical and mechanical components or array designs to disperse and filter light,” said Hoon Hahn Yoon from Aalto University’s Department of Electronics and Nanoengineering, who co-led the study. “Moreover, it can achieve a high resolution comparable to benchtop systems but in a much smaller package.”

The device is 100% electrically controllable regarding the colors of light it absorbs, which gives it massive potential for scalability and widespread usability. “Integrating it directly into portable devices such as smartphones and drones could advance our daily lives,” Yoon said. “Imagine that the next generation of our smartphone cameras could be hyperspectral cameras.”

Those hyperspectral cameras could capture and analyze information not just from visible wavelengths but also allow for infrared imaging and analysis. “It’s exciting that our spectrometer opens up possibilities for all sorts of new everyday gadgets, and instruments to do new science as well,” Minot said.

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