What if you had a hand-held gadget for analyzing the chemical composition of any substance merely by pointing to it and pressing a button? You could scan your food for allergens, your drink for alcohol and your medications for potential drug interactions.
To do that you would need a portable molecular spectrometer. Spectroscopy is a technique for recognizing physical materials by their spectral signatures – how their molecules react to different wavelengths in radiant energy. Spectroscopy can be performed with visible, infrared (IR), or ultraviolet (UV) wavelengths, but it is the near-infrared (NIR) region that yields particularly rich information about molecular vibration modes.
In principle, a spectrometer collects the light that is either reflected from – or transmitted through — the sample, and breaks it down into its constituent wavelengths with a diffraction grating. This allows a detector – either an array or a single element – to measure light intensity by wavelength, thus establishing the material’s signature. The problem is that array-type detectors are expensive. Single-element detectors are cheaper, but fragile; they require the grating to be rotated so different wavelengths can be sequentially detected.
If portable spectrometers can be made robust and inexpensive, they could be used at the edge of the IoT network to gather and transmit valuable information.
Texas Instruments DLP® technology may be the ideal solution. A digital micromirror device (DMD) is inserted into the optical path to steer light. By selectively turning columns of mirrors on or off, it can reflect only the desired wavelengths to a single detector: Speedy wavelength selection with no moving parts, in one fell swoop.
TI’s battery operated DLP NIRscan™ Nano Evaluation Module incorporates a DMD, a diffraction grating, and a single element detector. The module can be linked to cloud databases over Bluetooth® low energy for real-time analysis of the sample’s signature. Try it for yourself. What will you scan?