University of Wisconsin-Madison engineers developed a pin-sized sensor that could detect chemicals by integrating it into the camera of smartphones. 

Spectrometers are devices that can identify the chemicals in substances depending on the fingerprint of light absorption and emission. Issues involving these involve being expensive and bulky that do not permit outside use.

The innovation of the scientists involves designing a minute spectrometer that allows integration with the camera of a mobile phone with still accurate results. 

The study was published in the journal Nature Communications in their March 4, 2019 issue. 

"This is a compact, single-shot spectrometer that offers high resolution with low fabrication costs," says Zhu Wang, who was among the team of electrical engineers that created the device.

Hyperspectral imaging allows gathering data regarding each individual pixel in an image for material identification. The researchers developed their device with hyperspectral imaging. 

Each element has its own spectral fingerprint that involves wavelengths of emitted or absorbed light. Spectrometers are used to identify unknown compounds as components of distant stars. 

The team was successful in designing spectrometers who measure 200 micrometers on each side. The device can also hyperspectral imaging.