|Time Required||Average (6-10 days)|
|Material Availability||A kit is available for your convenience from our partner Home Science Tools. Estimated project time includes time to ship the kit.|
|Cost||Low ($20 - $50)|
|Safety||Adult supervision is required when cutting the head off a toothbrush.|
AbstractHave you ever wanted to build your very own robot from scratch? Bristlebots are a cheap, easy, and fun-to-build robot made from the head of a toothbrush, a battery, and a small motor. Once completed, they buzz along the top of a table like bugs. How can you make a bristlebot go faster? In this project, you will build bristlebots from two different types of toothbrushes, and race them against each other to find out.
Build one bristlebot with straight bristles and one with slanted bristles, and race them to see which is faster.
Ben Finio, PhD, Science Buddies
This project is based on the following post by Evil Mad Scientist Laboratories: http://www.evilmadscientist.com/2007/bristlebot-a-tiny-directional-vibrobot/
Cite This Page
Last edit date: 2017-10-16
Have you ever wanted to build your own robot? What about tiny robots that you could race against each other? In this science project, you will build and race bristlebots, tiny robots built on the head of a toothbrush, like the ones shown in Figure 1.
Figure 1. Two bristlebots racing against each other.
The bristlebot uses a small electric motor to move. In order to power the motor, the robot also needs a battery. When you connect the battery to the motor, you complete an electrical circuit. This makes a tiny weight inside the motor spin, causing it to vibrate. When the motor vibrates, it causes the robot to shake and buzz along the tabletop. This is the same type of motor that makes video game controllers and cell phones vibrate.
In this science project, you will build two different bristlebots: one with slanted toothbrush bristles, and one with straight bristles. Then you will race them against each other to see which one is faster!
Terms and Concepts
- What makes the motor vibrate?
- How can a vibrating motor make something move?
- Which do you think will go faster: a bristlebot with straight bristles or one with slanted bristles?
This project is based on the following post by Evil Mad Scientist Laboratories:
- Evil Mad Scientist Laboratories. (2007). Bristlebot: A tiny directional vibrobot. Retrieved August 6, 2014, from http://www.evilmadscientist.com/2007/bristlebot-a-tiny-directional-vibrobot/
If you want to learn more about some of the concepts in this project, like circuits and vibrational motion, check out these references:
- Henderson, T. (n.d.). Vibrational Motion. The Physics Classroom. Retrieved August 12, 2014, from http://www.physicsclassroom.com/Class/waves/u10l0a.cfm
- Grusin, M. (n.d.). What is a Circuit?. SparkFun Electronics. Retrieved July 31, 2014, from https://learn.sparkfun.com/tutorials/what-is-a-circuit
News Feed on This Topic
Bristlebot Robotics Kit, available from our partner Home Science Tools.
You will need these parts from the kit:
- Coin cell battery (2)
- Vibration motor (2)
- You will also need to gather the following materials, which are not included in the kit:
- Toothbrush heads (2), one with slanted bristles and one with straight bristles, with the handles cut off
- Double-sided foam tape
- Three large, heavy textbooks
- Flat, smooth surface like a table or countertop. The robots will not work on rough surfaces or carpet.
- Optional: Stopwatch
- Lab notebook
Building Your Bristlebots
- Get an adult to use strong scissors or pliers to help you cut the heads off two toothbrushes, one with slanted bristles and one with straight bristles.
- Follow the steps in this slideshow to build two bristlebots:
- If you prefer, you can watch an assembly video that shows you how to build your bristlebots.
- Follow these troubleshooting tips when using your bristlebot:
- Do not let the exposed metal parts of the red and black wires touch each other directly. This will create a short circuit and drain the battery very quickly, and will prevent the motor from vibrating.
- If your robot stops moving suddenly, check to make sure that one or both sets of wires did not come loose. This will create an open circuit and prevent the motor from vibrating. Tightly twist the wires back together if this happens.
- If your robot falls over a lot, make sure the motor and battery are centered on top of the toothbrush. You can also let the robot run continuously for 5–10 minutes, and it will slow down slightly as the battery begins to drain.
- To turn your bristlebot off, just untwist one set of wires (you do not need to disconnect both). Make sure you turn your robot off when not in use to conserve battery power.
Racing Your Bristlebots
- Make a racetrack for your bristlebots by setting up three large books on a smooth, flat surface, as shown in Figure 2. This creates two "chutes" that will force your bristlebots to go straight.
Figure 2. Racing chutes for bristlebots, made using three large books.
- Get ready to race your bristlebots! Reconnect the wires for each robot to turn them back on.
- Test your bristlebots in your racing chutes. If the chutes are too narrow, your bristlebots might get stuck. If they are too wide, they might spin around or fall over. Adjust the width of the chutes, if necessary.
- Pick up your bristlebots and place them side by side in your racing chutes.
- Let go of both bristlebots at the same time. Watch closely to see which one makes it to the other end of the chute first.
- If one robot goes backwards, flip it around and start over.
- Record the winner of the race in your lab notebook.
- Repeat the race four more times, for a total of five trials. Make sure you record your results in your lab notebook.
- Optional: Use a stopwatch to record how long it takes each bristlebot to go down the chute. Have a volunteer help if it is too difficult to use a stopwatch and control both bristlebots at the same time.
- Analyze your results.
- Does one bristlebot consistently win the race?
- How do your results compare to your prediction about which type of bristlebot would be faster?
Looking for more robot fun? Explore the World of Robotics with This Suite of Projects!
For troubleshooting tips, please read our FAQ: Racing Bristlebots: On Your Mark. Get Set. Go!.
Communicating Your Results: Start Planning Your Display BoardCreate an award-winning display board with tips and design ideas from the experts at ArtSkills.
Keep the fun going! Find local opportunities related to this project.Register on ActivityHero
If you like this project, you might enjoy exploring these related careers:
Robotics EngineerHave you watched "The Transformers" cartoon series or seen the "Transformers" movies? Both shows are about how good and evil robots fight each other and the humans who get in the middle. Many TV shows and movies show robots and humans interacting with each other. While this is, at present, fantasy, in real life robots play a helpful role. Robots do jobs that can be dangerous for humans. For example, some robots defuse landmines in war-stricken countries; others work in harsh environments like the bottom of the ocean and on the planet Mars. At the heart of every robot is a robotics engineer who thinks about what a robot needs to do and works with several engineering disciplines to design and put together the perfect piece of equipment. Read more
Mechanical EngineerMechanical engineers are part of your everyday life, designing the spoon you used to eat your breakfast, your breakfast's packaging, the flip-top cap on your toothpaste tube, the zipper on your jacket, the car, bike, or bus you took to school, the chair you sat in, the door handle you grasped and the hinges it opened on, and the ballpoint pen you used to take your test. Virtually every object that you see around you has passed through the hands of a mechanical engineer. Consequently, their skills are in demand to design millions of different products in almost every type of industry. Read more
Electrical & Electronics EngineerJust as a potter forms clay, or a steel worker molds molten steel, electrical and electronics engineers gather and shape electricity and use it to make products that transmit power or transmit information. Electrical and electronics engineers may specialize in one of the millions of products that make or use electricity, like cell phones, electric motors, microwaves, medical instruments, airline navigation system, or handheld games. Read more
Robotics TechnicianRobots are no longer futuristic machines. Robots are here and now and are used in manufacturing, health care, service industries, and military applications. They perform tasks that are repetitive and hazardous—things that humans don't want to do or are unsafe to do. But robots are still machines, which means they require humans to build, maintain, program, and keep them functioning efficiently. Robotics technicians work with robotics engineers to build and test robots. They are responsible for installing and maintaining robots and keeping them in working order for their employers. If you are interested in working with robots, your future is here and now. Read more
- Try building more bristlebots with even more types of toothbrushes. Which toothbrush head works the best?
- If you would like to build a larger robot that works on the same principle as the bristlebot (vibrational motion), check out the Science Buddies project Art Bot: Build a Wobbly Robot Friend That Creates Art. The electronic parts required to build an Art Bot are already included in your Basic Vibrobot kit from Science Buddies.
- If you would like to try a more advanced project, you can build a light-following bristlebot in the Build a Light-Tracking Bristlebot project.
- Instead of using a chute, make a circular "arena" for your bristlebots to let them move around freely. Set up a video camera directly above the arena, looking down, and use it to record the bristlebot's motion. Then, analyze the video with a computer and make plots of the path each bristlebot follows. Do the paths seem totally random, or can you identify any patterns? For example, do certain bristlebots tend to always turn in one direction?
- Make a "maze" for your bristlebots and time how long it takes different designs to find their way out of the maze.
Looking for more robot fun? Explore the World of Robotics with This Suite of Projects!
Frequently Asked Questions (FAQ)
Ask an ExpertThe Ask an Expert Forum is intended to be a place where students can go to find answers to science questions that they have been unable to find using other resources. If you have specific questions about your science fair project or science fair, our team of volunteer scientists can help. Our Experts won't do the work for you, but they will make suggestions, offer guidance, and help you troubleshoot.
Ask an Expert
Contact UsIf you have purchased a kit for this project from Science Buddies, we are pleased to answer any question not addressed by the FAQ above.
In your email, please follow these instructions:
- What is your Science Buddies kit order number?
- Please describe how you need help as thoroughly as possible:
Good Question I'm trying to do Experimental Procedure step #5, "Scrape the insulation from the wire. . ." How do I know when I've scraped enough?
Good Question I'm at Experimental Procedure step #7, "Move the magnet back and forth . . ." and the LED is not lighting up.
Bad Question I don't understand the instructions. Help!
Good Question I am purchasing my materials. Can I substitute a 1N34 diode for the 1N25 diode called for in the material list?
Bad Question Can I use a different part?
News Feed on This Topic
Looking for more science fun?
Try one of our science activities for quick, anytime science explorations. The perfect thing to liven up a rainy day, school vacation, or moment of boredom.Find an Activity