There is a bit of a disconnect in the minds of many people between static electricity, and the electrical power that we run our lives with. Are they the same thing? Or is static electricity, like the funny “bone”, simply a misnomer.
First, static electricity is electricity. Sort of. Electricity simply refers to the flow of electrons through something which will support their flow. Electrons are tiny particles which are a major part of how we experience the world. Typically, they exist in a difficult to quantify state in what is known as the electron cloud, in an area around the nucleus of atoms. However, in certain conditions, they can become unbound to nuclei, and flow. This happens most commonly in metals, which do not hold their electrons tightly. Conversely, materials which are good insulators like to hold their electrons tightly.
Static electricity occurs when electrons transfer from one material to another. This can happen for a variety of reasons. However, when electrons build up on one surface, they are liable to “jump” down a path of low resistance. When they find such a path, we can experience a small shock.
An extreme example of this is lightning in thunderstorms. During these extreme weather events, charges can become segregated within the storm. This creates immense buildups of energy, and lightning can arc from very negative areas in the cloud, to very positive areas, equalizing some of the charge between them. Less commonly, this can occur between a cloud and the ground. This immense discharge of energy can have devastating effects on anything in the area which cannot easily dissipate the energy. Lightning strikes can start fires, kill humans and other animals, or destroy things at or near the point of impact.
Visualizing static electricity as a miniature lightning bolt can help you to understand its effect on electrical components. Modern electrical components (think circuit boards) contain an incredible level of detail. Microscopically manufactured components work together, blending materials with different conductive properties into an intricate and fragile weave. While the amount of energy in a small electrostatic discharge (ESD) might seem barely noticeable to us, the amount of energy can be catastrophic to a circuit board. This energy can be far beyond what the circuit is designed for, and can destroy the components it touches, often shorting out or bricking the entire system.
Modern electronic devices are designed such that ESD from every day use will not reach the sensitive components. They are well protected by cases and covers which ensure that the sensitive interior is kept separate from the potentially electrically volatile exterior. However, people who work on these devices must ensure that there is no ESD, as the components are vulnerable when removed from the protective housing.
One way that this is accomplished is through the use of an ESD strap, which is simply a small bracelet or other tool which serves to ground the body of a technician working on a sensitive component. If any static electricity builds up, it has the opportunity to flow easily though the bracelet, and into the ground to which the bracelet is attached. Because there is no opportunity for electrical buildup, there is a much lowered risk of inadvertent ESD. They also use a variety of other different tools, such as mats which specifically are designed to minimize the risk of ESD, special gloves, and many other tools depending on the sensitivity of the equipment they need to work on.
Another risk of static electricity is not to electronics, but as a Firestarter. Static electricity has been known to ignite highly volatile gases such as vaporized gasoline. This is why modern automobiles have a number of regulations and safeguards in place, both to prevent gasoline from excessively building up as a vapor, and also to prevent users from inadvertently creating an electrical gradient. If you get a small shock when refueling your car, in the worst case scenario this could send the entire gas station up in flames.
Thankfully, because static electricity is so common, most things in our lives are safeguarded against the occasional small bit of electrostatic discharge. However, if you ever need to get into a computer (perhaps to remove a hard drive), keep what you learned here in your mind. Remember to ground yourself while removing the drive, and take steps to prevent any electrostatic activity when you are storing it. Avoid things like carpets or other synthetic materials, and try to do your best not to touch the more sensitive parts of the component you are handling. Similarly, remember that electrostatic discharge is a possibility any time you are working with highly flammable material or gases. Sometimes, what you don’t know can be very dangerous. It may be small, but all forms of electricity can be quite powerful, in the right set of circumstances.