Piezo design references - Page 1
Forum section: electronics / beginners

author: Aggressive_Doughnut
author_rank: Contributor
timestamp: May 04, 2019, 12:19:52 pm
content: I have seen quite a few papers using small piezo driven devices (e.g.this uses a tuning-fork-type device). I think it would be fun to try to build something like this, but I can't seem to find a resource for design. Specifically, I understand piezo driven oscillation in things like crystal oscillators, but I don't see how this can be used to drive a device like a fork tine (maybe somehow apply a voltage across its base?). Any reference would be much appreciated.

author: jeremy
author_rank: Super Contributor
timestamp: May 04, 2019, 01:08:53 pm
content: A good google search on this is “piezo actuator”. The company “Physik Instrumente” (PI) is well known for building devices that use this principle, and there should be lots of white papers around. The mechanisms are quite ingenious, like little micron sized legs walking around. The PI YouTube channel has some fantastic animations on how they work.You can buy PZT (lead zirconate titanate) discs on eBay for basically nothing from china if you are interested in playing around with them.Essentially, when you apply a voltage across a piezoelectric crystal, it deflects. You take the voltage away, and it goes back to its original position. The mechanical system will have a resonant frequency (well, at least one) where the amplitude of deflection is greatly increased; if you drive the crystal with a voltage of this frequency, you will get a crystal which deflects and relaxes the maximum amount.This is how piezoelectric “beepers” work; you have a piezoelectric crystal driven by an oscillating voltage, generating a pressure wave inside an acoustic cavity which is also resonant at the mechanical resonant frequency.

author: lyncse
author_rank: Newbie
timestamp: January 31, 2022, 04:05:42 pm
content: ...some necro-bumping in this threadAs for mine experience with the PI, I could say that the aftermarket support for most stuff you could purchase on eBay except maybe actuators themselves is virtually non-existent. There are two hard points - if the controller or the part of the controller is custom-made, which is not possible to verify prior to purchase, the PI themselves would refuse to provide *any* kind of support without written permission from the original owner (which is quite unfriendly way for low-budget aftermarket users such as myself as most other vendors I've used to work with do require proof of ownership in most extreme case) and the controller itself would not work out of box with PI software or third-party OSS such MicroManager due to custom additions to the signaling protocol.I've stepped in that pit not long ago, ordering E712 controller chassis with very nice P752 nanopositioner and obtaining a couple of C863 controllers with mechanical stages from the other source - none of them worked out of box due to being 'custom-made' by claim from the PI and in the same time PI refused to give literally any bit of information on this hardware prior to obtaining beforementioned written permission from the original owner, so I couldn't say that I'll ever recommend purchasing aftermarket PI hardware. Though C863s seem to be relatively easy to reverse on the comm quirks, the nanopositioner's controller system is far more complex and I'll probably would end trashing it, leaving >1K$ behind.

author: mawyatt
author_rank: Super Contributor
timestamp: January 31, 2022, 04:47:03 pm
content: Yes, PI wasn't much help, actually no help at all!!!So we set out to develop everything ourselves, here's the details of the development. As you can see we were able to achieve almost unbelievable performance into the nanometer regions and even had to develop a measurement technique to "infer" such!! This technique utilized a special adaptation of an optical alignment technique utilized in image stacking, see details in Closed Loop thread. Here' a snip that shows a total range of movement of 200 nanometers in 25 steps!!Part Ahttps://www.photomacrography.net/forum/viewtopic.php?f=25&t=40679&p=255768&hilit=Physik#p255768Part Bhttps://www.photomacrography.net/forum/viewtopic.php?f=25&t=40681&hilit=PhysikPart Chttps://www.photomacrography.net/forum/viewtopic.php?f=25&t=40682&hilit=PhysikClosed Loophttps://www.photomacrography.net/forum/viewtopic.php?t=40510