Piezoresistive effect

Have you ever noticed that when you squeeze a balloon, it gets smaller? That's kind of like what the piezoresistive effect is!

You know how some things like rubber bands and springs can stretch and then go back to their original size? Well, some materials are the opposite - they get smaller when they're squeezed, and bigger when there's less pressure on them.

When this happens, the material's electrical properties change too. So, if we put a tiny sensor made of this kind of material inside something, like a car tire, it can measure how much pressure is in the tire by looking at the electrical signals that it sends out.

This piezoresistive effect isn't just useful for measuring pressure in tires - it can be used in all sorts of things, like medical equipment, robots, and even smartphones.