In this blog post, we explore how electrical engineering—the fusion of electricity and information technology—is transforming modern society and how it is applied across diverse fields.
What do you think the ‘Department of Electrical Engineering’ studies? Typically, when people hear the word ‘electricity,’ they first think of static electricity, something you might feel on a cold, dry winter day. They also think of the power that operates lights, allowing people to be active in bright spaces on dark nights, or the electricity used to run household appliances that make life easier. The examples just mentioned aptly describe electricity, an essential commodity of modern society that we encounter frequently around us. However, people often struggle to grasp what happens when electricity and engineering come together.
Long ago, it was called the ‘Department of Electrical Engineering,’ but recently it changed to the ‘Department of Electrical and Information Engineering.’ Why change the name? What connection is there between electricity and information? While there were likely multiple reasons for the name change, I’d like to explain what kind of research happens in the Department of Electrical Engineering through the reason I believe is most significant.
In electrical engineering, ‘electricity’ can be broadly divided into electricity as energy and electricity as a signal. I am particularly interested in the field dealing with electricity as a signal, and this technology has advanced significantly, to the point where it greatly impacts other industries. It even finds application in the field of electrical energy itself. To explain the electrical energy field first, it’s easier to understand energy as a power source that moves objects.
As energy, electricity is produced at power plants, transmitted nationwide, and used to operate various devices. Therefore, those specializing in electrical energy research how to efficiently generate electricity, how to store this energy source in batteries, and how to minimize losses and transmit electricity cost-effectively.
Compared to other energy sources, such as thermal energy, electrical energy is highly organized. This allows for long-distance transmission with minimal loss and makes it suitable for conversion into other forms of energy. Because electrical energy is so well-suited to handling the vast amounts of energy humanity uses, life without electricity in modern society is unimaginable. All of this is thanks to the contributions of power engineers.
Now, let’s explain electricity as a signal. Electricity as a signal is a more comprehensive concept than electricity as power. First, considering the definition of a signal, in electrical engineering, a signal can be defined as a physical quantity that conveys information. Specifically, among various physical quantities like temperature, speed, sound, and pressure, it refers to voltage that conveys information. There is the field of signal processing, which efficiently receives signals and processes them into a form we can understand, and there is the field of communications, which deals with devices like radios or telephones that send and receive these signals. It is, quite literally, the discipline that deals with signals themselves.
To use these technologies easily anytime and anywhere, we need more sophisticated techniques. There is the field of circuitry, which creates circuits to amplify and store signals that have been sent far away via communication and thus diminished in strength. There is also the field of semiconductors, which manufactures the semiconductor devices that compose these circuits. Furthermore, there is the field of electronic physics and devices, which creates devices capable of converting processed signals into visual displays. Finally, there is the systems field, which ensures these devices operate reliably as a system, and the computer field, which processes the information contained within the signals. Therefore, electricity as a signal is not merely voltage; it is precious information that must be handled with great care.
Recently, the research areas within electrical engineering have expanded significantly, requiring considerable space just to introduce the subfields. This time, we will explain the electrical engineering technologies applied to MRI. MRI is an amalgamation of electrical engineering technologies. Fundamentally, MRI requires a powerful electromagnet. You probably remember from elementary school science class making an electromagnet and seeing the pattern drawn by iron filings drawn to it. The electromagnet built into an MRI is far more powerful, which is why you know you cannot bring any metal objects into an MRI scan.
This powerful electromagnet aligns the water molecules in our bodies along the direction of its magnetic field. In fact, although we rarely perceive it, over 90% of all forces in the universe are electromagnetic forces. Electromagnetic forces are usually in equilibrium, making them difficult for humans to sense. However, when this equilibrium is disrupted, phenomena like static electricity or lightning occur. Returning to MRI, when water molecules in equilibrium receive electromagnetic waves of a specific frequency, they begin to vibrate. This is similar to the resonance effect where plucking a string on a stringed instrument produces a specific note. That’s why MRI is called ‘Magnetic Resonance Imaging’.
When stimulated, the vibrating water molecules emit electromagnetic waves at specific frequencies. The intensity of these emitted waves varies depending on the water density within the body’s tissues. Using this principle, a receiver captures the signals, estimates the structure of the body’s tissues, and converts this information into an image that a doctor can interpret. Early MRI machines took a long time to acquire signals, sometimes causing patients to experience claustrophobia.
Initially, electrical engineers specializing in signal processing dedicated themselves to MRI research to reduce patient discomfort and enable faster imaging for more patients. As a result, images nearly indistinguishable from the original could be obtained using significantly fewer signals than before. Recently, MRI technology has advanced to the point where real-time observation of heart movement is possible. This technology plays a major role in dramatically processing biological information.
Thus, electrical engineering now encompasses not only the electronic devices deeply embedded in our lives but also medicine, 3D imaging, information processing, and even artificial intelligence. Under the name of electricity, it is expanding into unimaginable realms. Moving forward, electrical engineering will evolve beyond simple signal processing into a field where computers process signals more intelligently.
