Pocket-sized lab: $10 Cambridge chip analyses substances with light
A tiny spectrometer from Cambridge identifies plastics, coffee and pills and in tests even measured blood sugar. It is still a long way from being a medical device.
Symbolic image · Photo: Jim Barton / Wikimedia Commons, CC BY-SA 2.0 (cropped and resized)
Researchers at the University of Cambridge have developed an optical spectrometer that measures just a few centimetres across and, they say, costs about $10. Such instruments split light into its wavelengths to reveal what a substance is made of, a job usually done by expensive benchtop lab equipment. The new chip uses a silicon nitride platform operating in the near-infrared between 1,200 and 1,700 nanometres and delivers measurements in under a second. The findings were published in Nature Photonics. Start-up GlitterinTech was also involved in the work.
In tests, the device correctly classified plastics, pharmaceuticals, coffee, flour and tea every time. It measured concentrations in solutions to an accuracy of about 0.01%, which the researchers said beat commercial benchtop instruments in those experiments. It also measured skin moisture, blood alcohol, lactate and blood glucose under realistic conditions and worked between minus 20 and plus 80 degrees Celsius. However, non-invasive glucose tracking over an extended period was demonstrated in only one participant, and further testing is needed before it could become a medical product. Project lead Qixiang Cheng said: “Our vision is to make spectrometry as ubiquitous as temperature or motion sensing.”