BrushBots

Concept: Simple Circuits
A simple circuit is a complete course of conductors through which an electric current can travel. Circuits provide a closed path or loop for the current to flow. To be a circuit, this path must start and end at the same point.

Read Aloud: Making Simple Robots by Kathy Ceceri

Ingredients:

      ·         Toothbrush
      ·         Double-Sided Foam Tape
      ·         Coin Cell Battery (CR3023)
      ·         Micro Pager Motor

 Demonstration:

      ·         Use cutters to clip the head off of a toothbrush.

      ·         Use scissors to cut double-sided foam tape into small square pieces.

      ·         Time battery wires to around 1" long. Use wire strippers to strip 1/4" insulation off the end of each wire.
      ·         Peel the backing off both sides of a piece of foam tape. Stick the battery firmly on top of the toothbrush head using the foam tape.
      ·         Peel the backing off the motor. Stick the motor firmly on top of the battery.
      ·         Twist one end of the motor wire together with one end of battery wire. Repeat.

Experiment:

·         What happens if you twist the red and black wires together?

·         What happens if you twist the red wires together and the black wires together?

Observations:
A brushbot is a very simple type of vibrobot that uses the head of a toothbrush as its body and the bristles as its legs. The key to the vibrobot movement is a motor that has an unbalanced weight. As the motor spins, the weight being off-kilter makes the motor vibrate. The brushbot moves by vibrating its body. Pager motors used to create vibration alerts in consumer electronics use this technique.