Make a Bubble Writer Toy (Write with Bubbles!)

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Bubbles are always a hit, and this Bubble Writer Toy is one of those simple projects kids never get tired of. We originally called it a bubble shooter, but once we realized you can actually write and draw with bubbles, the name stuck.

Kids can spell words, draw pictures, and experiment with bubbles — all while learning about air pressure and bubble science. This is also a super simple STEM project for kids using supplies you already have at home.  . (Find more of our STEM projects here.)

How to Make the Bubble Writer Toy

This is SO easy to put together! Grab a ball point pen that is out of ink. We all have them lying around. Then take it all apart. You will take out the tube that has the ink inside and also the writing tip. If your pen has a cap on the top end, remove that, as well.

You will also need a large balloon, a rubber band, and a pan of soapy water.

If there is any ink remaining in any part of the pen, soak it in a bowl of rubbing alcohol for a bit to get it all off. You don’t want to get ink in your mouth and you will be blowing on this pen. Make sure to rinse the parts after soaking them, too.

Then add the balloon to the top end of the pen and secure it tightly with a rubber band. Remove the tip and blow up the balloon through the pen end.  Once the balloon is blown, twist it to keep the air in and place the tip of the pen back on.

Have your pan of soapy water ready to go!

Scribble, write, and draw in the soapy water. Do your spelling words with the bubble shooter!

You will need a few minutes between each use to let the bubble die down a bit and blow the balloon back up.

My kids went nuts over this project and have been playing with it for days.

The Science Behind the Bubble Writer Toy

This simple bubble writer is a fun way to explore several important science concepts through hands-on play.

1. Air Pressure

When you blow into the pen, you increase the air pressure inside the balloon. Air always moves from an area of higher pressure to lower pressure. As the air escapes through the narrow opening of the pen tip, it pushes through the soapy water and forms bubbles.

2. Surface Tension

Soap lowers the surface tension of water, allowing it to stretch without breaking. When air pushes through the soapy water, the water forms a thin, flexible film around the air, creating a bubble.

Without soap, the water would break apart instead of forming bubbles.

3. Bubble Formation

Bubbles form when air is trapped inside a thin layer of soapy water. The size and shape of the bubbles depend on:

• How fast the air is pushed out

• The size of the opening

• The thickness of the soap film

With the bubble writer, the narrow pen tip creates a stream of small bubbles that can be “drawn” across the surface of the water.

4. Flow Rate and Speed

Blowing gently creates slower air flow and smaller bubbles. Blowing harder increases the flow rate and creates larger or more energetic bubbles. Kids can experiment with how changing the force of their breath changes the bubbles they make.

5. Engineering Design

This project is also a simple example of engineering design:

• The pen acts as a tube to direct airflow

• The balloon stores air

• The rubber band creates a seal to prevent air leaks

You can challenge kids to redesign the bubble writer using different tubes, straws, or containers and compare results.

6. Why the Balloon Needs Refilling

As air escapes, the pressure inside the balloon drops. Once the pressure is too low, bubbles stop forming, and the balloon needs to be reinflated. This shows how stored energy (air pressure) is used up during the process.

Want more BUBBLE Activities?

See our Bubble Blower Machine Engineering Project
Learn How to Make Square Bubbles
Try Color Mixing in Bubble Wrap