Bristlebots Resources

Materials

Checkout from Kart:

  • Main Cabinet: Soldering Iron
  • A1: Toothbrush
  • A1: Foam Tape
  • A2: Vibrating pager motor
  • A2: Coin Cell Battery
  • A2: Copper Wire

Lesson Plan

Introduction

The BristleBot activity serves as a good opener to lessons on electricity, motion, or robots. Robotics and physics clubs may also find it a fun after-school activity.

Using the BristleBot in a classroom or extra-curricular setting will vary, based on grade level. Teachers can make one and bring it to class to demonstrate for younger students. Older students can build the BristleBots on their own. Or, teachers may assemble and distribute the materials for a guided class activity. Depending on the age group, and for safety, teachers may wish to solder the copper wire leads onto the motor ahead of time.

Extension

Engage students in a discussion of their procedure and techniques, to explore difficulties encountered, as well as ingenious solutions.

Then, challenge them to consider — and devise — design modifications. What would happen if the toothbrush bristles were not straight? What could be done to the BristleBot to make it go in circles? Could a similar vibrobot be made from a flat-topped dust broom or a hair comb?

Student Instructions

  1. Cut off the handle of the toothbrush to produce the robotics platform.
  2. Attach short copper wire leads to the motor, either soldering them to the motor terminals, or securly affixing them with heavy tape.
  3. Apply a small piece of foam tape to the top of the toothbrush robotic platform to hold the motor in place.
  4. Attach the motor to the foam tape. The tape provides a spacer so that the rotating weight does not hit the toothbrush head. It also provides a strong, flexible connection to the base that is able to handle the severe vibration that this robot experiences. BristleBot Almost Completed
    1. Do not stand the battery on end, as it will be insecure and fall off easily.
    2. Instead, bend one of the leads flush with the foam tape, so that you can stick the battery to the foam tape, as well, and still make an electrical connection.
    3. The other lead contacts the other side of the battery, and the motor can run.
  5. Refinements: The completed BristleBot is now running and ready for action. When it is set down, it may tend to steer left or right.

Battery and motor placement, bristle shape, and even one stray bristle can interfere with the motion. Encourage students to experiment with each of these elements, to get their Bristlebot to run straight. Motor rotation direction can also influence the behavior, so it may help to flip the battery upside down.

Once the BristleBot is going straight, it will continue on until it hits something, which will turn it and send it off in another direction. Several BristleBots can race across a room at once, creating a fun group activity.