Make Oobleck! A Non-Newtonian Fluid

Oobleck is cool!   If your kids have not yet explored “Non-Newtonian liquids”, then they should make Oobleck!

A non-Newtonian liquid demonstrates variable viscosity, which means that the viscosity (or “thickness” of the fluid) may change as force is applied or, less commonly, over time. A Newtonian liquid such as water has a constant viscosity.

Examples of non-Newtonian liquids include ketchup, syrup and Oobleck. Ketchup becomes runnier, or less viscous, the more you shake it. Oobleck is just the opposite – the more you play with it, the harder (more viscous) it becomes!

How to make a Non-Newtonian Fluid:

• Mix Cornstarch and water.
• Optional: Food Dye and popsicle stick stirrers.
• Toys to experiment with: Strainers, Paperclips, Cotton Balls, spatulas, etc.

There is not an exact amount of water or cornstarch ratio.   We just grabbed a box and poured cornstarch into cups, added food dye and water.

You are looking for a consistency that cracks when you shove your stirrer through it quickly, but “melts” back into the cup.

Oobleck Activities:

Turn your cup of oobleck upside down quickly, what happens to it??   It should stay in the cup even if the cup is not upright until force is applied to the cup, breaking the colloid tension.

Fill a strainer with Oobleck.   Watch how it slowly drizzles out.   If it stops dripping, what happens if you stir the goo??

Pour a layer of goo into the bottom of a casserole dish.   Slap the Oobleck mixture.   Does it act like water and splash?   Try to hit it harder.   What happens??

Can you take a spatula and lift a “slice” of oobleck off the plate?   What happens?

Are you looking for even more activities?   Check out this collection of things to do with oobleck.

.

We drizzled our oobleck over cotton balls and then baked them in the oven until they dried out.   One of our boys loves hammering and his younger, not ready-for-nails brother wants to join him.

We made cotton balls to hammer with our oobleck today.