Jacuzzi

OK, I think that'll be the last of my vibration levels. They do make for a naughty little challenge, but I can't say if it's particularly fun being thwarted when all you're trying to do is take a step forward. If anyone is interested in encorporating such jiggles into their designs, I'll leave a note here on how they are achieved.

If you place a metal sloped brick on top of a FD and then put a zapper on top, when you press play you'll notice the FD and sloped brick quickly move away from being directly under the zapper. So we can box them in so that they are trapped under the zapper. They then remain in an unstable state: desperate to get out from under the zapper but blocked from doing so. They will vibrate. If you also attach a metal platform to the sloped brick, the platform will vibrate, but its a little unpredictable, it'll stop and start. Adding a rotation element under the FD will ensure constant vibrations.

Here is a picture of both types of vibration device, continuous and sporadic. Both might be used to fun effect in different designs.
https://imgur.com/a/7QEeadF

@Marv Beautiful design!
Also, instead of Z in this design, you can use the Eye. The eye, just like Z, pushes blocks from below

@Denis Nazin that's actually neater, 2 stacked elements instead of 3, although also a lot wilder