6/15/16- Non-Newtonian Fluid

So, I had been "shopping" around an article about how to do a Non-Newtonian Fluid experiment to different kid lit magazines.  Unfortunately, I had no bites.  I believe so much in the value of STEM outreach and doing STEM experiments/activities with students, that I've decided to go ahead and share the article here on my blog.  It's also a good activity for a hot summer day, so I hope you enjoy it at home!

Water is a liquid.  Corn starch is a solid.  What happens when you mix the two?  You get a mixture that is between a solid and liquid. It becomes a Non-Newtonian Fluid.   Let’s get ready for a fun, messy experiment!

Supplies you will need:

1. Box of Corn Starch
2. Water
3. Measuring cups
4. A container to mix in—we used a disposable pie tin, but a mixing bowl, measuring cup, or cake pan work too
5. Spoon
6. Food coloring (optional)
7. Paper towels, paper ads, paper table cloth, or newspaper to cover your working surface to make clean up easier!

Okay, here you go!  First place the mixing container on your work surface or countertop.  Then pour a ¼ cup of corn starch into the container.  Next prepare a ¼ cup of water.  You’re going to slowly add the water to the corn starch in mixing container, alternating between adding the water and stirring the mixture in the mixing container with a spoon.  You’re trying to find a mixture that is similar to honey or syrup as we stir.

The ideal mixture will be liquid when you’re stirring it, and then feel hard when you give it a quick tap with the spoon or your finger.  Go ahead, give it a quick tap!  Is it hard?  If not, then add a little pinch of corn starch. 

You’ve got the right feel?  Great!  Now pick some of it up and roll it around in your hands as if forming a ball.  Does it harden into a ball or fall apart? What happens when you put the ball back into the mixing container and stir?  Does it go back to a liquid?

A Non-Newtonian Fluid is a liquid as pressure is applied to it. But apply a different pressure, and it may become solid.  Which one is it? Solid or liquid? It can be treated as both a liquid and a solid!  The reason is because of Non-Newtonian Fluid’s changing behavior under stress (or pressure).  Other examples of Non-Newtonian Fluids are ketchup, Silly Putty, and quicksand.

Having fun with Non-Newtonian Fluid!

Here are some other ideas to try:

1. Dragging the spoon through it—solid or liquid feeling?
2. Get a straw and blow on top of it—what do you observe?
3. Try breaking it up in the container with the spoon—are you able to?
4.  Push your whole hand into the mixture (within the container) and then remove your hand from the mixture—did your hand stick or easily come out?
5. Add food coloring—do you what colors to add together to make green? Purple? Orange? Brown?
6. With permission from your parents or guardians, look up videos online of “Non-Newtonian Fluid dancing.”
7. Come up with your own ideas to test.  Playing around and getting messy with the Non-Newtonian Fluid is part of the fun!

When done experimenting, don’t forget to clean up!  Hope you enjoyed not quite a liquid, but not quite a solid, Non-Newtonian Fluid!