lungs working model science project exhibition


In this project, we will create a working model of the lungs to demonstrate the breathing mechanism using a DC motor, balloons, and syringes. This model will help visualize how the lungs expand and contract during inhalation and exhalation.

Materials Needed:

  1. Two balloons (different sizes)
  2. Two syringes (20 ml or larger)
  3. DC motor
  4. Battery pack for DC motor (with switch)
  5. Rubber tubing
  6. Cardboard or foam board
  7. Straws
  8. Tape
  9. Glue
  10. Scissors

Step-by-Step Explanation:

  1. Creating the Base:
    • Cut a piece of cardboard or foam board to create the base of the model.
    • Attach the DC motor to the base using tape or glue.
  2. Attaching Balloons to Syringes:
    • Attach one balloon to the open end of each syringe using rubber tubing or straws.
    • The balloons will represent the lungs.
  3. Creating the Ribcage:
    • Cut two curved strips from cardboard or foam board to represent the ribcage.
    • Attach the curved strips to the base, on either side of the DC motor.
  4. Connecting Balloons to Motor:
    • Attach the other ends of the rubber tubing or straws to the DC motor’s shaft.
    • As the motor turns, it will cause the balloons to inflate and deflate.
  5. Assembling the Model:
    • Attach the syringes with balloons to the cardboard ribcage, ensuring that the balloons are positioned like lungs.
    • Make sure the balloons can inflate and deflate without any obstructions.
  6. Powering the Model:
    • Connect the DC motor to a battery pack with a switch.
    • Turn on the switch to power the motor.

Demonstrating the Breathing Mechanism:

  • When the motor turns, it will create a flow of air through the rubber tubing, causing the balloons (lungs) to expand and contract.
  • As the balloons inflate, it demonstrates inhalation, and as they deflate, it demonstrates exhalation.
  • Explain that this model mimics how our diaphragm and intercostal muscles work to expand and contract the lungs during breathing.


By building the lung model, you’ve successfully created a visual representation of the breathing mechanism. This project allows viewers to understand how the lungs expand and contract during inhalation and exhalation, enhancing their understanding of the respiratory system.

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