Unit 10 Lesson 2: Robotics

If you’ve ever wondered how to build a real robot from junk, then you’re in the right place. Let’s start by taking a look at the highlights for understanding electricity, circuits, and components and how they all work together to form a working robot.

Now that you’ve got a good handle on circuits and electrical components, it’s time to pull it together into something useful, like building robots and sensors. Are you ready? Then let’s put your new ideas and electrical circuit building skills to the test…

You can get started by watching this video, and afterward either read more about it or start your experiments!

Scientific Concepts:

  • Robots are electro-mechanical devices, meaning that they rely on both electronics and mechanics to do their ‘thing’.
  • If a robot has sensors, it can react with its environment and have some degree of intelligence.
  • Sensors include switches, buzzers, and light detectors.
  • One of the biggest hurdles to overcome when building robots is friction.
  • A radio remote control has a transmitter and receiver that pass light beams to control the robot.
  • A wired remote control is a box usually containing the batteries and switches for the connected robot.


Science Teleclass: Robotics
This is a recording of a recent live teleclass I did with thousands of kids from all over the world. I’ve included it here so you can participate and learn, too! Spark together electric motors, build homemade burglar alarms, wire up circuits and build your own robot from junk! Create your own whizzing, hopping, dancing, […]
Amphibious Robot
Amphibious vehicles is a craft which travels on both land and water. And it doesn’t need to be limited to just cars. There are amphibious bicycles, buses, and RVs. Hovercraft are amphibious, too! Amphibious crafts started back in the 1800s as steam-powered barges. In the 1950s, the German Schimmwagen was a small jeep that could […]
Propeller Car
The great news is that many of the problematic airplane troubles were figured out a long time ago by two amazing people: the Wright brothers. The Wright brothers also took an airfoil (a fancy word for “airplane wing”), turned it sideways, and rotated it around quickly to produce the first real propeller that could generate […]
Bristle Brush Bot
This is the simplest robot you can make… out of old parts from around the house. While this little robot doesn’t use energy from the sun or wind, we’ve placed it here with other alternative energy projects because the parts come from the trash bin. This project is an extension of the Jigglebot robot from […]
ROV stands for Remotely Operated Vehicle. These robots are used by scientists to explore the waters both offshore and in the deep sea, and often bring back samples and/or take video of their underwater findings. ROVs usually have a tether from the vehicle to the boat, which lightens up the load quite a bit (as […]
Ever wonder how a cell phone vibrates? What mechanism could be in such a tiny space to make the entire phone jiggle around? Well, there’s a tiny motor inside with an off-center weight on the shaft, called an eccentric drive. You can still see eccentric drive mechanisms in older steam engines where the rotational motion […]
If you have a pet, they’ll be sure to get a great workout chasing this nifty little robot. If you can, I totally encourage you to make two or more and have a contest! This BumperBot is one of the simplest robots you can make that uses a touch sensor, tricycle gear, and simple parts […]
Race Cars
Racerbots can steer, unlike the Jigglebot. If you have more than one motor on your robot frame, you can turn either left, right, or spin on command. Wired remote control instructions follow this project. These racerbots are the toughest of these robots to build. The wheels need to be squarely set on their shafts, all […]
Superfast Bug Bot
This project is advanced students. If you like tiny robots, then this one is for you! Powered by cheap hobby motors, this fast little robot zips ’round and avoids obstacles using momentary switches and an idler wheel for a tail. I recommend watching the entire video first, then rewind and watch again, this time building […]
Underwater R.O.V. Robot
This project is for advanced students. Up until 200 years ago, people thought the oceans were bottomless.  The diving bell was one of the first recorded attempts at undersea exploration, and was simply a five-foot inverted cup with viewing holes on a platform that lowered into the water, which allowed people to breathe the trapped […]
Pressure Sensor Burglar Alarm
By controlling how and when a circuit is triggered, you can easily turn a simple circuit into a burglar alarm – something that alerts you when something happens. By sensing light, movement, weight, liquids, even electric fields, you can trigger LEDs to light and buzzers to sound. Your room will never be the same. Switches […]
Latching Circuit
Once you’ve made the Pressure Sensor burglar alarm, you might be wondering how to make the alarm stay on after it has been triggered, the way the Trip Wire Sensor does. The reason this isn’t as simple as it seems is that the trip wire is a normally closed (NC) switch while the pressure sensor […]
Trip Wire Burglar Alarm
Burglar alarms not only protect your stuff, they put the intruder into a panic while they attempt to disarm the triggered noisemaker.  Our burglar alarms are basically switches which utilize the circuitry from Basic Circuits and clever tricks in conductivity. A complete and exhaustive description of electronics would jump into the physics of solid state […]
More Sensors
If you want your robot to detect when it’s flipped sideways, this is the sensor you need. It’s ridiculously simple to make, and works great as long as the metal makes good contact. I’ve also included instructions for making a motion sensor as well, just in case you need to detect motion or acceleration.
Electrical Safety – A Note on the Best Batteries to Use
Before you reach for the pack of Duracells, watch our video on the best batteries to use when starting out with your electricity experiments. (The answer is much cheaper than you think.) Here’s what you need to know: