Oobleck Chladni Plate!?!?
Introduction: Oobleck Chladni Plate!?!?
What is a Chladni plate?
No, it is not some fancy serving platter that you get from your great aunt that you never put on your wedding registry.
No, it is not ... (alright lets get serious)
A Chladni plate seems simple at first glance it is just a thin plate with a low friction surface excited by oscillation but sometimes it is the simplest things that lay bare the most amazing phenomenon. This is a tool for visualizing and understanding the impact that resonance can have on the world. When you excite this simple metal plate to any number of resonant frequencies a few things will happen:
1. You will wish that you had ear plugs because single tones produced by it are not very pleasant.
2. You will wonder what is so special about this thing until you realize it is a tool to interact with other matter.
3. Finally you put some powder or other small particles on the plate while it is a resonating
1. Then just like every car seat or couch you have ever sat in the material mysteriously starts to collect in different places. The difference being that what you dropped in your car seat is gone forever while the sand on the Chladni plate is arranged into a beautiful resonant frequency mosaic.
Hopefully you are asking yourself a question along the lines of, "What is happening and why?" Just like my Rubens' Tube projects in the links below this is a manifestation of resonant standing waves but in this case we have moved from a one dimensional Rubens Tube into two dimensions with a Chladni Plate. 70
I am also going to be looking at something I have no seen before and that is if we can generate a negative pattern on the Chladni plate using a non-Newtonian fluid like Oobleck!!!
https://www.instructables.com/id/Music-Controlled-...
https://www.instructables.com/id/Rubens-Tube-Flexi...
Lets look at what parts and tools we need and then in Step 1 I will go into greater detail about what is happening here.
FTC Disclaimer: I earn a percentage of the sales through the affiliate links provided through Amazon.
If you click on the link it helps fund future projects but bear in mind it might not be the best price for this materials.
Supplies
Materials
* Bluetooth or Wired Audio Amp
* Acoustic Exciter
* Plastic Tub (I used this to make clean up easier and to reuse the powder)
* 12" x 12" Metal Plate
* 1/4" x 2" Brass Drive Bolt
* 3x 1/4" Brass Nut
* 4x #6-32 1 1/2" Brass Machine Screw
* 4x #6-32 Brass Nut
* Sand Blasting Media
* Dry Lube
* 3D Printed elements (Connector between the Acoustic Exciter and the bolt)
* Sheet of Scrap wood ( I used some 1/4" plywood I had laying around)
* Glossy Black Spray Paint
* Electrical Tape
* Wire
* Frequency Generator App on your phone
* Super Glue
Tools
* Drill
* 3D Printer
* 5/32" Drill Bit
* 1/4" Drill Bit
* Ruler
* Marker
* Wire Cutter
Step 1: How a Chladni Plate Works?
There are so many demonstrations of Chladni plates on the internet, too many to list. Some are excited with a violin bow and others with speakers and still others with specially designed drivers. While you are likely able to find someone that explains it better me I am going to do my best to explain what is happening here.
Close your eyes and picture a a smooth pond surface. It is mirror-like. Now drop a small pebble into the water and watch the ripples in the water radiate away from the point of impact until they dissipate so they can no longer be seen. This is the start of what is happening with a speaker driven Chladni plate. The bolt in the center is like the pebble dropped into the water with waves radiating outer wards. However, unlike our example the waves do not have space to dissipate in the plate before they hit the edges and this is where things really get shaken up. At the edge some of the energy that is vibrating through the plate reflects backward towards the center of the plate where the vibration began like an echo in a canyon or like the rigid end cap in a Ruben's Tube.
We can try to understand this by going back to the placid pond in our minds and instead of dropping one pebble we drop two pebbles a small distance apart. 582