I am hoping to analyse vibrations occurring in a MEMS device, and calculations indicate I will need to measure frequency and amplitude between 1 - 150 kHz range. The sensors I have looked at (e.g., accelerometer) top out around 20 kHz. What might one suggest?
-Ryan
I understand that you are interested in finding the frequency response (frequency vs. amplitude plot) of a MEMS device. Instead of using a separate sensor, you may go for a characterization equipment called Laser Doppler vibrometer (LDV). It can detect out-of-plane vibrations up to 24 MHz. In case you are interested in in-plane vibrations, stroboscopic video microscopy may be used. It can support frequencies up to 1 MHz. Both these features are available in Polytec Micro System Analyzer (MSA-500).
I agree with Ankush. Laser doppler vibrometry is the best and probably unique solution for your application. Take into account that measurements with LDV have the fundamental feature of non-contact. You can operate without any influence (such as unbalanced masses) on your object.
I think LDV is a good idea - one problem with contact sensors would be the mass added, which for a MEMS device can be significant. However, the testing technique is extremely important. You need to ensure there is no boundary condition influences.
LDV can be good solution for directional vibration. For relatively high frequencies, on field, the support of the sensing device can give severe disturbances. a "cut-off" filtering base isolation can be very useful. .
LDV is excellent, and we do this in our laboratory routinely; you would need a microscope arrangement (or a specific LDV system with microscope already built in, such as MMAs from Polytech) to reduce the spot size of the laser (and thus, the spatial resolution of your measurements). Please note that there are also recent laser-interferometer systems (non Doppler) that may be able to measure this frequency range.
You can use a MEMSMap 510 XYZ from www.optonor.com for both out-of-plane vibration measurements and in-plane vibration measurements up to 240 mHz
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