Strain gauge

A strain gauge is a little device that helps measure how something is stretching or getting squeezed. It's kind of like a tiny rubber band that stretches along with the thing it's attached to, and when it stretches it sends a signal to a machine that helps calculate how much it stretched.

For example, imagine we wanted to measure how much a bridge is bending when a car drives over it. We might attach some strain gauges to the metal beams that make up the bridge. As the car drives over the bridge, the strains gauges would stretch along with the metal beams, and we could use the signals they send to a machine to figure out how much the bridge bent.

Strain gauges are really useful because they can help us measure really tiny changes in shape that might be hard to see with our eyes. But they're also delicate and have to be used carefully to make sure we get accurate readings.