Something great doesnt always need to be big. Sometimes it can also come in small sizes, infact really small sizes. Now talking of toy boats, they are either powered by springs, candles, electric motors and such. But if the boat gets really small, like around 2cm, then you need a completely different propulsion system.
These micro boats use a surfactant for propulsion. The movement is by marangoni effect. The boat floats on water due to surface tension. The surfactant placed at the end of the boat slowly dissolves in water and creates a difference in the surface tension of nearby water, causing water to flow away from the back of the boat, hence moving the boat forward.
Here we shall be using camphor as our surfactant. we can also use soap water or acetone. But, since camphor is solid, it runs for a longer time
Step 1: 1.Materials
You will need:
1. Plastic sheet or metal sheet (0.2 to 0.3mm thick). I prefer plastic because it is lighter, hence boat moves faster.
2. Camphor, it is very cheap and available at any retail shop.
4. Paint (arylic or oil paint).
5. Brushes, pen, etc.
6. A large plate or tray.
Step 2: 2.Draw
Simply draw the outline of the boat you want on the plastic or metal sheet. Drawing the outline helps while cutting it out. A tapering and smooth front end is suggested to reduce drag and increase speed. Also dont forget the small notch at the back of the boat, we will insert the camphor there.
Step 3: 3.Cutting
Carefully cut out the outline of the boat. Now you can see how small it is.
Step 4: 4.Propulsion
Break a small piece of camphor and insert it into the notch as shown. press it together so that the camphor holds on to the notch. Now, at this stage the boat is fully functional. But a transparent boat wont look good on water, so lets colour it up.
Step 5: 5.Painting
Remember to use acrylic paint or oil paint so that the colour does not wash off in water. Simply colour as you like. Here i have painted it black and orange. And if you notice, the black is matt finish.
To create matt finish take a cotton swab, dip it in colour and dab it lightly on the boat. keep on dabbing until you get a matt finish.
Step 6: 6.Detailing
Detailing is also upto you. You can do anything you want. Here i have detailed with orange stripes and a white piece of thin plastic as windshield. Again, whatever glue or colour you use must be waterproof.
Step 7: 7.Prepare the Pool
Get you plate or tray and put clean water in it. Clean water is important as it has maximum surface tension. If impuritues like soap or alcohol are present, they will make the surface tension so low that the boats will not move at all. But you need not use purified water. Ordinary fresh tap water will do.
Step 8: 8.Hit the Water
Put the piece of camphor into the notch of the boat. Gently release it on the water surface keeping the painted side upward and see the boat run.
A single piece of camphor will run the boat for around 15 minutes. After that the boats will slow down because too much camphor would have been dissolved in water, thus lowering the surface tension. To start it again just change the water.
After you have successfully made one, you can get into its diversity. The boat can be made of different shapes, different sizes, different colours and what not. You can make a speed boat, a dinghy, a kayak or even a ship. You can make more notches at the back to add more camphor and boost the speed. And after you have made a few, put them to race. In this olympics season, create your own olympics. Just the basic propulsion system is same, but the CREATIVITY is upto you. Enjoy..