Simple home experiment to discover Non-Newtonian fluid
When you strike a liquid, it parts. That’s how we swim, drink, wash and do everything with liquids. But some liquids do exactly the opposite of others when struck – they solidify! These strange fluids are called Non-Newtonian fluids.
What is a Non-Newtonian liquid?
According to Newton, ‘normal’ liquids have a constant viscosity, i.e., a flow. This flow changes only with change in temperature. As we all know, liquids evaporate beyond boiling point and turn solid below freezing point. But when we apply force or stress to Non-Newtonian fluids, for example we tap on their surface, they behave like a solid! And when we remove the stress, they behave like liquid again! One unexpected Non-Newtonian fluid is a mix of corn starch or makki ka atta and water.
The experiment
Introduce your kids (and the child in yourself) to this strange phenomenon with a simple home experiment today.
What you’ll need
- A bowl
- Half cup corn starch
- 1/3rd Cup water
Get these on a table, call your child, and start the experiment.
How-to
Here’s a step-by-step description of the experiment:
- Mix the corn starch and water in the bowl
- Stir it slowly till you get a gooey mix
- Now ask your kids to tap the mixture with their finger. It will feel hard, like a solid!
- You can add more water or corn starch, to keep the mix consistent. But it will always behave in the same strange way, i.e. it will behave like a liquid when stirred and feel like a solid when struck or tapped
Now that your child is really surprised, explain what happened.
How does corn starch create a Non- Newtonian fluid mix?
Corn starch or maize starch is derived from the endosperm of the kernel. It is a common food ingredient, used widely to thicken sauces, soups, and gravy, also as corn syrup. But this everyday ingredient is more versatile than we think. Once it was discovered that corn starch has the odd property to push together molecules and create a solid surface when mixed with water, the Non- Newtonian fluid found more usage. It’s now used in industrial products such as adhesives, paper products, as an anti-sticking agent, and in textile manufacturing.