Piezo actuators

A project log for AR Glasses

low power laser projector for AR glasses to display vector graphics

JoelJoel 06/16/2021 at 17:263 Comments

The piezo ceramic actuators finally arrived. They are miniscule. For my first tests, I glued them to an aluminium plate and glued a mirror on top. I hope they work as intended, because I only have a few. The mirror I am using is a regular glass mirror, and has to be replaced with a dedicated laser mirror in the future, but it will be enough for testing purposes. I haven't made any calculations so it's very much possible that this design will not work at all. All I have to do now is to find a high voltage source.

piezo array
piezo array with mirror


Mark Jeronimus wrote 07/11/2021 at 12:40 point

I doubt these will work as you imagine. I've in the past tore down a piezoelectric focus plate, which is a device that can move up or down 0.1mm while staying perfectly parallel. That device contains four piezo-piles like the ones you have but about twice as long, and they're each mounted inside of a rigid-flexible aluminum casing that amplifies the motion (to the 0.1mm amplitude) through levering action. I suspect each piezo-pile will only elongate/contract in the micrometer range.

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nagup wrote 06/20/2021 at 16:19 point

Would the laser mirror have the reflective coating on the surface or behind some glass like this current mirror? I found that the glass adds some refraction and produces a double image.

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Joel wrote 06/21/2021 at 14:00 point

thats exactly the point. The reflctive coating needs to be on top

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