Ink-powered leaf boat
This is a really fun experiment showing how little boats made of leaves can be powered by ballpoint pen ink!
What you will need:
Leaves
A ballpoint pen
A deep tray or shallow container
Water
Kitchen towel or paper for cleaning up
What you need to do:
First you will need to find some leaves to use as boats. Small leaves are best as they will have more room to move about in a container. Try and make sure the leaves lie flat.
Set up a container or deep tray filled with water.
Take your ballpoint pen apart by removing the casing and then pulling off the nib. You should now be left with a tube of ink.
Next you will need to apply the ink to the tail end of one of the leaves. The ink is fairly thick and sticky so it won’t come out of the tube easily on it’s own. To get to the ink you can blow through the non-inky end until you see the ink bulge out of the other end and then you can dab this onto the end of the leaf. Alternatively, you can tap the inky end of the tube onto a piece of scrap paper a few times until the ink starts to come out.
Make sure that you dab the ink on the underside of the leaf as the ink needs to touch the water for this to work!
Place your leaf on the water and watch how the ink propels the leaf boat forward leaving a colourful inky wake behind it!
The reason the leaf is propelled forwards (or at least in some part) is because of surface tension. The ink has a lower surface tension than water and so the surface tension at the tail end of the leaf is lower than at the front which creates a ‘pull’ at the front of the leaf, making it move forwards.
You can also try different coloured or branded ballpoint pens to see how this effects how the boats move and how the ink disperses in the water.
To clean up after you have finished the experiment, you can lay a few pieces of kitchen towel on the surface of the water to pick up the ink which you can then put into the bin before you pour the water away. Most of the ink will easily wash away with washing up liquid and water but any remaining ink can be cleaning with surgical spirit, alcohol-based hand sanitiser or acetone nail polish remover.
Author: Denise Hope, home educating mum of two boys
If you’d like to receive regular nature craft activities alongside gardening activities for children, subscribe below to receive a monthly Mud & Bloom box! Each monthly Mud & Bloom box contains at least two craft activities for children as well as two growing activities.