Visualising Dynamic Displacements of Micromachined Devices
We have demonstrated using a commercial white light interferometric microscope, a Wyko NT-2000 surface profiler, to visualise the dynamic motion of a micromachined device. This involves the relatively simple modification of replacing the standard halogen bulb with an LED source to operate stroboscopically, synchronised to the drive signal of the micromachined device.
![Schematic of experimental setup](wykosch.gif)
Schematic of experimental setup.
The results shown here are all for a sinusoidal excitation. The devices move at twice the excitation frequency as the electrostatic driving force depends only on the magnitude of the signal.
![1K excitation 0ms](wyk1k0.gif)
![1K excitation 0.3ms](wyk1k200.gif)
![1K excitation 300ms](wyk1k300.gif)
![Cross-sectional profiles at various intervals for 1kHz and 10 kHz excitation.](wykoprofiles.gif)
mpeg movies for 1Khz , 10kHz and 20kHz drive signals.