I don’t know if you have seen such a video on the Internet recently. Five broken toothpicks are placed together. When they encounter water, they automatically form the shape of a five-pointed star. It is very magical. In this regard, the Institute of Physics of the Chinese Academy of Sciences conducted an experimental demonstration and explained the principles.

Experimental equipment required:Toothpick, dropper, water, plastic pad, labeled cup.

first step:

Take 5 toothpicks and fold them in half, but be careful not to break them completely, leaving a little connection.

Step two:

Place the toothpicks on the plastic mat and arrange them in the shape of a five-petaled flower. The tips of the five toothpicks face outwards, spread out in a V shape, and come together in pairs.

Step three:

Use a dropper to drop a small amount of water at the center joint of the toothpick. Try not to drip too much or to the outside of the toothpick.

After a few minutes, the opening of the toothpick gradually enlarged on its own and slowly turned into the shape of a five-pointed star.

This is actually the phenomenon of self-assembly. By rationally designing the structure of the toothpick arrangement and using dripping water to drive it, the rearrangement of the toothpick structure is achieved, which involves infiltration and capillary action in physics.

Toothpicks and paper have a wood fiber structure. When one side encounters water, the capillary action of the fiber structure will cause water to be sucked in along the fiber.

The side of the toothpick that touches the water shrinks due to the tension of the water, but the dry side does not, so the toothpick gradually opens toward the water, and the five-pointed star blooms as we see it.

It should be noted that if too much water is added at one time, or it is added to the outside of the toothpick, this effect will not occur.

in addition,When the water gradually soaks the entire toothpick/paper, and when it is completely wet, the tension at both ends will cancel out, so if you break them back to their original state, they will not bloom again.

In addition to toothpicks, you can also use matchsticks, wooden sticks, etc. to achieve the same effect.