Static electricity is a phenomenon that causes objects to become electrically charged. We experience it every day when we brush our hair or take off our winter clothes, and it’s used in a wide variety of industries, including photocopiers, smoke filters, and clothing manufacturing.
You may have noticed that when you comb your hair with a comb, the hair sticks to the comb and makes the strands stand up. This is due to static electricity. Static electricity is especially common during the winter months, as the air becomes drier and more prone to static electricity. Because dry air doesn’t conduct electricity well, static electricity lingers long after it’s generated. This is why you feel a tingling sensation on your fingertips when you put on and take off knitted clothes in winter, or when you open and close your car door.
When an object becomes electrified, it is said to be “electrified,” and when the electricity in an electrified object stops flowing somewhere else, it is called static electricity. Static electricity occurs in many different situations in everyday life, and its principles are simple but fascinating. The phenomenon of static electricity was known as far back as the ancient Greeks, who observed that when they rubbed a pumpkin with a cloth, small objects would stick to it. As you can see, static electricity has a long history in our lives.
Why does it happen? The atoms that make up matter are composed of positively charged nuclei and negatively charged electrons. Normal matter has an equal amount of positive and negative charges, making it electrically neutral. When two different objects rub together, some electrons are transferred from one to the other, leaving the object that received the electrons negatively charged and the object that lost the electrons positively charged, creating static electricity. However, like charges repel each other and unlike charges attract each other, so even charged objects will repel objects with the same charge and attract objects with different charges.
This property of static electricity is widely utilized in industry. For example, to remove dust in the electronics manufacturing process, static electricity is used to attract and repel dust. Paint shops also use static electricity to evenly distribute paint on the surface of a car. As you can see, static electricity is useful in many different fields. Static electricity also plays an important role in semiconductor manufacturing. In order to keep semiconductor chips clean, it is essential to remove microscopic particles, which is done using the power of static electricity. This greatly improves the performance and lifespan of semiconductors.
A photocopier, a staple of modern society, is a typical device that utilizes this property of static electricity. The inside of a photocopier consists of a cylindrical drum with a positively charged photoresist, a negatively charged toner, a moving light source, a heat source, and a number of elaborate rolls. Of these, the drum and toner are the most obvious examples of the properties of static electricity.
When you place the document you want to copy on a transparent glass plate and press the copy button, light passes under the glass plate. The black parts of the document absorb the light and the white parts reflect it, forming a phase on the cylindrical drum. The surface of this cylindrical drum is positively charged. However, when light hits the surface of the drum, the areas where the light hits become uncharged because the positive charge on the surface of the drum is neutralized by the negative charge inside the drum. Therefore, only the areas that have not received light remain positively charged. When negatively charged toner approaches the drum in this state, only the positively charged areas will attract and adhere to the toner powder. If you pass a piece of paper under the drum and apply a positive charge to the paper that is stronger than the charge on the surface of the drum, the toner powder will fall off the drum and transfer to the paper, forming text. The writing formed on the paper will only last as long as there is static electricity. To make the writing stick, the paper is pressed into a hot roll (over 180°C), and the copying process is complete.
Static electricity has many other applications beyond photocopiers. It can be used to induce static electricity in the filters of a smog filter to trap fine dust. It can also be used to electrostatically charge the exterior materials of a spacecraft so that they have the same charge as space dust, which can help solve the problem of space dust sticking to them. Static electricity is also used in the clothing manufacturing process. Static electricity can be used to align and organize fibers to produce high-quality fabrics. This helps to make clothing more durable and more comfortable to wear. As you can see, the scientific principle of static electricity is widely utilized in everything from photocopiers to spacecraft to clothing manufacturing. More recently, researchers have also been working on energy storage using static electricity. Attempts are underway to utilize the properties of static electricity to develop more efficient batteries, which could play a major role in solving future energy problems.
As you can see, static electricity plays an important role in our lives, industry, and the advancement of science and technology. It is fascinating to understand how static electricity, which can be perceived as a minor inconvenience, actually contributes to our lives in so many different ways. New technologies that utilize static electricity will continue to emerge in the future, making our lives more convenient and enriching.
