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Eureka! Toothbrush Robots

A_ToothbrushNote:  This is the part of a series of posts about science activities to be done in the bathroom – the lav-oratory if you will.  

In my last bathroom science post we made toothpaste – this time I’d like to look at the toothbrush.  There are a couple of standard “toothbrush” experiments:

  • staining an egg (or something else to represent your teeth) and seeing how well different toothpastes and/or toothbrushes remove the stain.
  • testing toothbrushes (and other parts of the the bathroom) for bacteria based on either location or length of use.  Check out this Mythbusters video for more.

But suppose you are looking for something a little different to do with your toothbrush?

Have you considered using your toothbrush to make a robot?

There are two variations on this concept but they are both based on the same idea.

Bristlebots at the starting line of a race.

The mini version consists of just the top of the toothbrush (the part with the bristles) on which is attached a small vibrating motor and battery.  When the battery is connected to the motor, the motor vibrates.  And since the motor is attached to the toothbrush, it vibrates as well.  Depending on the orientation of the bristles, your robot will move.

A larger version consists of a scrub brush with an electric toothbrush attached to the top.  The electric toothbrush is really just a vibrating motor with a battery so essentially this is the same as the first robot, just larger.

If you’ve every shopped for a toothbrush you will notice that the bristles come in dozens of configurations.  Some are straight, some are angled and some have various combinations of these.  Some toothbrushes even have thicker rubber bristles on them.  The question is “How does the configuration of bristles affect the motion of your toothbrush robot?

Science buddies has instructions for making the basic “bristlebot” as they call it, along with variations including light-tracking and solar powered bristlebots.  What other variations can you come up with? Can you figure out a way to control or drive your bristlebot?

The origin of this type of motion goes back to the 1940s before video games when a popular toy called “Electric Football” was introduced.  Although the game stopped production in the 1980s it is still popular.  There is even a Miniature Football Association for enthusiasts of the game.

The game consisted of a vibrating metal plate on which football players with small prongs on the bottom – similar to the toothbrush bristles.  The vibrating plate would cause the players to move.  Rookie players had fixed prongs but other players had a dial that allowed you to adjust the direction of the prongs and thus the direction the layer moved on the field.  Could you devise something similar for your bristlebot?