MEMS based Spectroscopy Systems

Miniaturised MEMS based spectroscopy systems#

© Fraunhofer IPMS
MEMS grating spectrometer: As small as a sugar cube.
© Fraunhofer IPMS
Design of a miniaturised MEMS spectrometer.

Fraunhofer IPMS develops miniaturised spectrometer systems for mobile use in a wide range of applications, e.g. in the agricultural and food sector, in pharmacy, biotechnology and medicine as well as in the environmental and recycling sector.

With a volume of only 2.1 cm³, the miniaturised grating spectrometer developed is about 30 % smaller than an ordinary piece of sugar cube and is currently the smallest NIR spectrometer in the world. Due to its compact design, a weight of only 17g and a low power consumption in the mW range, it is ideal for integration into mobile analysis devices for on-site measurements. In the realised design, it addresses the NIR spectral range of 950-1900 nm with a spectral resolution of 10 nm.

Whether freshness testing of foodstuffs, sorting of plastic objects in recycling, determination of the type and concentration of starting materials in pharmacy or measurement of the composition of gases and liquids in the combustion tract of vehicles: in each case, the aim is to qualitatively and quantitatively determine the type and concentration of the materials involved in the most time-saving way possible. Spectroscopy, in which substances are illuminated and the intensity and wavelength of the reflected light are analysed, is predestined for all these applications. This is because measurement by means of electromagnetic radiation is contact-free, leaves the sample undamaged and is equally suitable for solid, liquid or gaseous substances.

The spectrometer uses a special discrete-time measuring principle which makes it possible to scan a spectrum with a single highly sensitive detector only by the rotational movement of the integrated MEMS grating. The central element of the spectrometer is a micro-electro-mechanical system (MEMS) measuring only (9.5 × 5.3 × 0.5) mm³ developed at Fraunhofer IPMS.