Robotics
Sensors explained with things in your kitchen
A fridge light, a kettle, a kitchen scale. Everyday examples that make sensors easy to understand.
A sensor is anything that notices a change and passes that information on. Robots use sensors to know where they are and what's around them. But you don't need a robot to understand sensors. Your kitchen is full of them.
The fridge light: a switch sensor
Open the fridge and the light comes on. Close it and it goes off. There's a small button in the door frame. When the door presses it, the light is off. When the door opens, the button pops out and the light turns on.
This is the simplest kind of sensor: on or off. Robots use the same idea to know when they've bumped into a wall.
The kettle: a temperature sensor
A kettle switches itself off when the water boils. Inside is a small strip of metal that bends when it gets hot. When it bends far enough, it pushes the switch off.
Ask your child: what would happen if the strip didn't bend? This is how engineers think about safety.
The kitchen scale: a weight sensor
A digital scale has a sensor that bends very slightly under weight. The more it bends, the higher the number. It's the same kind of sensor a robot arm uses to know how hard it's gripping.
A little experiment
Put a bowl on the scale and press zero.
Add one spoon of sugar at a time and write down each number.
Ask your child to guess the next number before adding the spoon.
That guess is the heart of robotics: reading a sensor, noticing a pattern, and predicting what comes next.
More sensors to find
The oven timer (time)
The smoke alarm (smoke particles)
The automatic tap in some bathrooms (movement or light)
In our Circuits & Sensors class, students build their own versions of several of these.
Thanks for reading
