DIY Science: Ink-redible Drawings

Learn the physics behind the properties of water, currents and friction.

Make Your Own Floating Masterpieces

Like a scene from a magical storybook, you can bring ink drawings to life and make them dance across ripples of water. Watch to find out how, and read on for a handy shopping list and the science behind it!

https://youtu.be/AcqMxorIb3Q

Everything you need to give this a try at home:

• Dry Erase Marker Pens https://amzn.to/3wK4svH

• Straws https://amzn.to/3UVtBxL

• Play-doh https://amzn.to/3UVYEcM

The science

The secret behind these floating masterpieces is caused by the interaction between density and surface tension.

Ink has a lower density than water, has its molecules spread out more loosely. This makes it lighter and allows it to float atop the denser water.

Surface tension, on the other hand, is the force that acts like a thin elastic membrane on the surface of a liquid.

When you draw on a surface that doesn’t absorb water, like a ceramic plate, using a dry-erase or whiteboard marker, the ink molecules stick to the surface.

Now, when you slowly add warm water to the plate, the surface tension of the water tries to pull the water molecules together, but the ink molecules are already bound to the plate.

This creates a thin film of ink that's less dense than the surrounding water, allowing your doodle to embark on its aquatic adventure.

This works because dry erase markers unlike permanent markers (e.g. Sharpies) are made with minimal adhesive. They are also insoluble in water, meaning they don't mix with water.

When you use the straw to blow air onto the drawing and water, you create a current that causes the water to ripple.

So you can watch in awe as your ink drawing comes gracefully to life on the water's surface.

We've loved sharing daily science tips and tricks with you during British Science Week 2024! Stay tuned for more DIY science, Behind-the-scenes and the latest science news.