New MOEMS based systems appropriate for spectroscopic investigations on agricultural growth and perishable food conditions

Further optimisation of the process of agricultural growth and quality control of perishable food, which can be fruits and vegetables as well as every kind of meat or milk product, requires new approaches for the sensitive front end. One possibility is reflectance or fluorescence spectroscopy in a wide wavelength range. By now broad usage is hindered by costs, size and performance of existing systems. Micro opto electro mechanical system (MOEMS) technology for scanning gratings used in Czerny-Turner spectrometers and translational mirrors for Fourier Transform Infrared (FTIR) spectroscopy enable small robust systems working in a range from 200nm to 5µm. Both types use digital signal processors (DSPs) capable to compute the spectra and execute complex evaluation and decision algorithms. The MOEMS chips are realized by etching of silicon substrate. Depending on the bearing springs a silicon plate up to 3 x 3 mm3wide and typically 30µm thick can be driven resonantly to rotational or translational movement. Combined with additional optical components and appropriate detectors handheld systems have been realized and tested. Results of first measurements of reflection spectroscopy on tomatoes are presented in the NIR wavelength range. Future systems may contain displays and light sources as well as data storage cards or additional interfaces.