Experiments with oobleck and homemade magnetorheological fluid

So i have tried to use the famous oobleck as a smart surface by making it harden under command by passing ultrasound waves through it, so what happened is well........NOTHING, turns out that you need a lot more acceleration to see any appreciable changes in its solidity.(tried out a small vibration motor as well, but as expected nothing happened).

Another failure is trying the same with a homemade magneto rheological fluid , but this time applying a magnetic field....still no appreciable results...but i think i will get a custom fluid form the metallurgy department and try more.Wish me luck.

The above picture is of the iron filings we collected from the construction site to make the magnetorheological fluids. we made acolloidal solution of this with vegetable oils.