More than half of the top 10 companies in the 2024 Global Enterprise Brand Value ranking are focused on electrical and electronic products, and these products are essential to our daily lives. Understanding the physics of electricity flow explains the role of conductors and semiconductors, how electronics evolved, and how capacitive touchscreen technology works.
In 2024, the global brand value ranking of companies includes Apple, Microsoft, Amazon, Google, and South Korea’s Samsung Electronics in the top 10. What do these companies have in common? They are all in the business of electricity or electronics. Now, let’s go back to the beginning of your day, when you wake up this morning. You roll out of bed, take a warm shower, and check your messages on your smartphone, which you left on its charger the night before. You eat breakfast, take public transportation to work or school, work on your computer under fluorescent lighting, and attend a meeting or lecture – all of which are powered by technology. Electricity is an essential element of our lives, and for more than half of the world’s top 10 companies, it is a critical resource that creates added value and enables their continued development and growth.
Let’s take a look at how electricity, which enriches our lives, works. All matter in the world is made up of ‘atoms’, which are composed of ‘nuclei’ and ‘electrons’. ‘Electrons’ can also be divided into electrons that are bound to the nucleus and ‘free electrons’ that move freely. When you apply a potential difference to an atom, the free electrons around the atom will flow to one side, causing electricity to flow. Let’s take a simpler example: there are marbles rolling around in a box. Think of these marbles as free electrons. On a flat surface, they roll freely. Now, if you lift one corner of the box, they’ll all come together at the other corner. If you imagine a very long tube instead of a box, the marbles would roll downward in unison, and this is the flow of electricity that we use.
According to the degree to which electricity flows, materials in the world can be categorized into ‘conductors’, ‘non-conductors’, and ‘semiconductors’. The ‘degree to which electricity flows’ can also be seen as the ‘amount of free electrons’ mentioned earlier. A conductor is a material that has many free electrons, so current flows well even if a small potential difference is applied. The metals we commonly use as wires are good examples of conductors. Conductors have few free electrons, so they don’t flow well when a potential difference is applied. Things like rubber and plastic are examples of conductors. Semiconductors are materials that allow current to flow “when certain conditions are met” that would normally make them non-conductors. They are usually made by synthesizing different materials and are used to power things like computer chips and other electronics.
So is your body a conductor or a non-conductor? We’ve all heard of people getting electrocuted or struck by lightning, and because the human body is a conductor, when there is a potential difference from the outside, electricity flows through the body. Until now, people have only thought of these ‘dangers’ when electricity comes into contact with the human body, so efforts have been made to reduce electrocution and leakage accidents. In contrast, a new technology has been created that utilizes the fact that the human body is a conductor: capacitive touchscreen technology.
Touchscreen technologies include pressure-sensitive, capacitive, infrared, and ultrasonic. In the early days of touchscreens, pressure-sensitive technology was heavily used. Since the pressure-sensitive technology receives the pressure of a person pressing on the screen as input, it has the disadvantages of being less durable and not being able to realize multi-touch. Therefore, ‘capacitive’ touch technology is widely used in smartphones, tablet PCs, etc. Electronic devices with capacitive touch technology have sensors with electrodes attached to the four corners. When a person touches the screen, electricity flows from their body, which is the conductor, to the sensors. Depending on where you touch and the distance to each sensor, the strength of the current the sensor receives varies. This allows the sensors to read the exact coordinates. Depending on the coordinates read in this way, the device can receive different inputs.
As the smartphone and tablet market has grown significantly, the technology of capacitive touchscreens has also been improving, with thinner membranes that allow current to flow through them than conventional touchscreens, reducing weight, reducing power consumption, and making batteries last longer. For now, touchscreens are simply being used to change the input method for existing electronics. However, as touchscreen technology continues to improve, it is expected that there will be many windows, showers, and portable IT devices with touchscreen functions that are made of a single piece of glass.
