What is Static Electricity?
Static electricity is electricity that is not moving (static). Rubbing or separating of two different materials typically causes it. One of the materials will become positively charged and the other will become negatively charged. Usually, at least one material has high resistively, that is, nonconductive; the charge will remain on the surface of that material. The static charge may be large enough that it will discharge when it becomes close enough to a grounding point. This electro static discharge (ESD) spark can injure personnel, damage electronic components and sensitive material and cause fires and explosions. In addition, when two similar charges are near each other they will repel and dissimilar charged materials will attract each other. Because of this attract/repel condition electrostatic charges and ESD will often cause major material handling problems.
Static electricity is NOT electricity which is static or unmoving. See Static Electricity Misconceptions Instead, “static electricity” is more properly known either as “High Voltage” or “charge-imbalance.” We could also call it “separated electricity” or “contact electrification.” Interesting things only happen whenever a large amount of positive charge is separated from a large amount of negative charge, and it doesn’t matter if the charges are moving. It’s the separation or imbalance which is important. The stillness or static-ness of the charge has nothing to do with it. To learn something about separated charge, see: explaining electricity with colored plastic sheets. Suppose you rub a balloon upon your arm. Hold it near your arm, and your arm hair stands up. You probably don’t realize that it requires around 100,000 volts to make your arm hair rise like that. Rubbing balloons upon arms can easily create potential difference of 100,000 volts or even more.
You’ll remember from Chapter 2 that the word “electricity” came from the Greek words “elektor,” for “beaming sun” and “elektron,” both words describing amber. Amber is fossilized tree sap millions of years old and has hardened as hard as a stone. Around 600 BCE (Before the Common Era) Greeks noticed a strange effect: When rubbing “elektron” against a piece of fur, the amber would start attracting particles of dust, feathers and straw. No one paid much attention to this “strange effect” until about 1600 when Dr. William Gilbert investigated the reactions of magnets and amber and discovered other objects can be made “electric.” Gilbert said that amber acquired what he called “resinous electricity” when rubbed with fur. Glass, however, when rubbed with silk, acquired what he termed “vitreous electricity.” He thought that electricity repeled the same kind and attracts the opposite kind of electricity. Gilbert and other scientists of that time thought that the friction actually created the
Return to SatCure-Focus Home page. Before handling electronic components, it’s important to realise that semiconductors can be damaged by high voltage “static electricity” carried on your body. The explanation I shall give is not quite technically correct but it will give you the general idea and allow you to understand the problems much better than a more involved discussion might. You have probably all seen a Van de Graaf generator at school or at science fairs. It has a moving rubber belt which transfers electrons from its base to a metal globe. If you touch the globe you will receive an electric shock because your feet are on the ground at zero voltage and your hand is touching the globe (not for long!) at 100,000 volts. The potential difference between your feet and hand is 100,000 volts. However, if you first stand on an insulating block, your whole body will be charged to 100,000 volts when you touch the globe. You feel no painful shock because the potential difference is now be
Everything we see is made up of tiny little parts called atoms. The atoms are made of even smaller parts. These are called protons, electrons and neutrons. They are very different from each other in many ways. One way they are different is their “charge.” Protons have a positive (+) charge. Electrons have a negative (-) charge. Neutrons have no charge. Usually, atoms have the same number of electrons and protons. Then the atom has no charge, it is “neutral.” But if you rub things together, electrons can move from one atom to another. Some atoms get extra electrons. They have a negative charge. Other atoms lose electrons. They have a positive charge. When charges are separated like this, it is called static electricity. If two things have different charges, they attract, or pull towards each other. If two things have the same charge, they repel, or push away from each other. So, why does your hair stand up after you take your hat off? When you pull your hat off, it rubs against your hai
