Experiment 5: Learning About Capillary Action
Capillary action is the ability of a liquid such as water or alcohol to move through tiny spaces or channels in a solid material. Let me give you a visual. Think of the MTR station. The train represents the liquid and the tunnel represents the tiny spaces in a solid object. Then imagine it becoming smaller and smaller and smaller and teeny tiny. Now, we can't really see both the train and the tunnel, but we know it's there. Same as we really can't see the particles that make up the water and the tiny spaces in the solids, but we know it is there.
The cool thing about capillary action is the liquid can travel or move through the spaces by itself. We don't need to blow or suck (as we do with a straw) to move the liquid. How is this possible? Well, liquids particles like to stick together and they also like to stick to the tiny spaces in objects. Think of a creeping vine. They stick to the walls of the tiny spaces and pull each other along the way. That's why liquid is able to "climb" up the paper towel in the photo. That is also why it can spread outward.
Why is capillary action important? For many reasons, but here are the top two. First, plants and trees need capillary action to allow water in the soil to climb up to the other parts of the plant, such as the stems and leaves. Second, capillary action helps bring blood to all our body parts, especially the ones that are furthest away from the heart such as toes and fingertips! We actually have teeny tiny blood vessels called capillaries!
Another cool thing about liquids and capillary action is that if there are other particles in the way, the liquid can "carry" them or push them along the way. That is how we are able to create art with capillary action. The ink of the marker pens have very tiny particles. When the liquid passes through, it takes along the tiny colored particles making really nice patterns!
The cool thing about capillary action is the liquid can travel or move through the spaces by itself. We don't need to blow or suck (as we do with a straw) to move the liquid. How is this possible? Well, liquids particles like to stick together and they also like to stick to the tiny spaces in objects. Think of a creeping vine. They stick to the walls of the tiny spaces and pull each other along the way. That's why liquid is able to "climb" up the paper towel in the photo. That is also why it can spread outward.
Why is capillary action important? For many reasons, but here are the top two. First, plants and trees need capillary action to allow water in the soil to climb up to the other parts of the plant, such as the stems and leaves. Second, capillary action helps bring blood to all our body parts, especially the ones that are furthest away from the heart such as toes and fingertips! We actually have teeny tiny blood vessels called capillaries!
Another cool thing about liquids and capillary action is that if there are other particles in the way, the liquid can "carry" them or push them along the way. That is how we are able to create art with capillary action. The ink of the marker pens have very tiny particles. When the liquid passes through, it takes along the tiny colored particles making really nice patterns!
The EXPERIMENT: Capillary Action Art
Our Objective: To make awesome patterns through capillary action!
Our Materials:
Our Materials:
- coffee filter paper
- white cloth (the best and most economical fabric I found was DITTE from the curtain section of IKEA -- cost HK$29.90/meter)
- different colored markers
- isopropyl alcohol (if you get water based markers, water will do)
- straw
- frame (some suggestions: paper cup, yogurt tub)
- tape
The Procedure:
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Take the filter paper and cut it down to size. I made mine into circles to fit on top of the yogurt container. Secure the filter paper on top of your frame with pieces of tape. Use the marker pens to make simple patterns on the filter paper. Do not draw on the filter paper too much or the result won't be as nice. Circular patterns work best! Pour a small amount of alcohol in a container. You don't need a lot! Cut the straw in half. Dip one end of the straw into the alcohol and then cap it with your finger. This will collect a small amount of alcohol. REMEMBER, YOU DO NOT NEED A LOT OF ALCOHOL -- a few drops only! Carefully put the straw on the center of your design and then remove your finger from the top of the straw. This will release the alcohol on to the filter paper. Now, for the fun part! Watching the liquid travel and spread the colors! |
For Parents...
Science is a great way to develop your children's critical thinking and logical reasoning skills! So, ask them to share what they did during science club. They should have brought home the products of the experiments or even some materials to do the experiment at home with you! Have a discussion about the experimental process and do extension activities! I promise that you will have as much fun as your children had and they will have a blast being your TEACHER!
Discussion Questions:
Extension Activities:
Discussion Questions:
- Why do you think the alcohol was able to "push" the marker colors?
- Do you think using the straw to get some alcohol is an example of capillary action? Why or why not?
Extension Activities:
- What other liquids (aside from water and alcohol), materials (aside from filter paper and cloth), and colored pens (aside from markers) can you use to create capillary action art? Share your work with me! My email address is: [email protected].