It’s winter again, and it’s time to fight against static electricity. Are you feeling irritated today?

With the arrival of the cold wave, most parts of my country have entered "winter mode". Whether it is the north with heavy snow and biting cold winds, or the south with freezing cold and urgent need for autumn johns, "static electricity" is a standard feature of winter.

The crackling sound when putting on and taking off a sweater, the flying sound when combing your hair, and even the trouble of "electric shock" when getting into bed are unavoidable. Today, let's uncover the true face of "static electricity" together.

Because of static electricity, the cat was covered with foam plastic

Source: Wikipedia

1

Static electricity and winter

We have long experienced the close relationship between static electricity and winter from the details of daily life. So why is static electricity only prone to occur in winter among all the seasons?

In fact, static electricity in life is mainly contact static electricity . A more vivid description is: when an uncharged object contacts an object with static electricity, the charge will either flow from a high potential to a low potential like water flowing to a low place, leaving the uncharged object with excess charge; or the charge will be redistributed in the object, causing different parts of the object to be charged. Humid air and metal objects will allow the charge to "escape", but in a dry and insulating environment, the charge is easily enriched.

Therefore, when winter comes, the dry weather provides a "good opportunity" for the generation of static electricity. In winter, the relatively dry indoor environment is a high-risk area for static electricity. When carpets, cushions, wallpapers, etc. are rubbed, static electricity will be generated. In particular, in order to keep warm in winter, people often wear sweaters and other clothes that are prone to static electricity.

At this time, if you accidentally touch the electrified water pipes, electrical appliances, metal door handles, TV screens or even switches with your hands, you will instantly feel the pain of being "electrically shocked".

The static electricity generated by friction with the slide causes the hair to repel each other

Source: Wikipedia

At the same time, in winter, we wear more clothes to keep warm. When these clothes of different materials rub against each other, or when clothes, body and hair rub against each other, charge transfer and accumulation will occur, causing potential differences in different areas of our body. These charges are difficult to release, and after accumulation, they will form high potential static electricity on the human body.

2

Static electricity and the human body

Static electricity is the electric charge accumulated in a charged body, which does not flow to form an electric current. Therefore, when it has no release path, it accumulates into a certain potential difference.

The human body carries static electricity. When holding a metal water bottle close to a metal box, discharge will occur, producing tiny electric sparks.

Source: Photographed by the author

In this way, when we touch the surrounding objects, a release path may be formed, and the accumulated static electricity is transferred outward through the contact point, forming a rapid discharge phenomenon, and even generating sparks . However, since the large resistance of the human body can resist the high voltage of static electricity, we don’t have to worry too much about being "electrocuted". The current generated by static electricity is not large and the duration is short. Generally speaking, it will not cause danger to the human body or endanger human life.

People's perception of static electricity increases in a step-like manner . When the static voltage reaches 2000 volts, the fingers can feel it; when it exceeds 3000 volts, sparks will appear and the fingers will feel a pricking pain; when it exceeds 7000 volts, people will feel an electric shock. At the same time, there are also data showing that when the static voltage is greater than 7000 volts, it will change the inherent potential difference in the human body and affect the function of organs. Therefore, static electricity will cause trouble to those who are more sensitive to pain.

You must have been electrocuted.

Source: Internet

In short, the feeling of being electrocuted is not pleasant. The static electricity or sparks generated by some chemical fiber underwear can cause itching symptoms on the skin. Another point worth our attention is that objects with static electricity are masters at absorbing dust. The large amount of static electricity on the TV screen is very easy to absorb dust in the air. When this dust falls on human skin, it is easy to cause skin diseases such as macules and acne.

3

Say goodbye to static electricity

So, what should we do when facing annoying static electricity? For a long time, people have had many tricks.

When dealing with static electricity on your body, you should first moisturize your body in the winter when the temperature and humidity are low. Apply body lotion and hand cream every day to moisturize the skin and prevent static electricity accumulation.

A small experiment on electrostatic adsorption

Source: Internet

At the same time, you can do something about the choice of clothes you wear. Chemical fiber clothes and sweaters represented by polyester, terylene, and acrylic fibers are prone to generate static electricity due to friction when putting on and taking off. Therefore, winter clothes (especially underwear) and household items can be made of pure cotton, linen, silk or other anti-static materials to kill static electricity in the cradle. Adding some fabric softener when washing clothes is also a relatively simple and effective method. Loose and soft clothes are a good helper to defeat static electricity.

Dry air is also a major cause of static electricity, so increasing indoor humidity is also a feasible method. We can choose to place a humidifier, one or two basins of water or anti-static spray indoors to make the dry air moist and reduce the possibility of static electricity.

To avoid the "magic" damage from static electricity, you can also "discharge" in advance . For example, before touching an object that may discharge electricity, first hold a wider metal key head or other small metal device with your palm, and then touch the metal door or window with the tip of the key (when shooting the video above, although there was an electric spark, the editor did not feel the obvious stinging sensation of "being electrocuted"). When touching things and people, you can extend your entire palm to touch them. This increases the contact area and greatly reduces the discomfort of static electricity generated by touching with your fingertips.

Source: Internet

Although static electricity is annoying in winter, it is not difficult to stay away from static electricity as long as you master these little tips.

It is worth noting that the greatest harm of static electricity is in production. Sparks generated by static discharge can easily ignite flammable and explosive objects, causing fires. Therefore, in special production environments, even common static electricity should not be taken lightly.

Audit expert: Luo Huiqian

Associate Researcher, Institute of Physics, Chinese Academy of Sciences

Source: Digital Beijing Science Center