In this blog post, we will take a look at how electrical engineering, which combines electricity and information technology, brings changes to modern society and how it is used in various fields.
What do you think of when you hear the word “electrical engineering”? When people hear the word “electricity,” they usually think of static electricity, which can be felt on a cold, dry winter day. And we also think of the power used to operate the lights that allow people to work in bright spaces at night or the appliances that help us in our daily lives. The examples mentioned above well describe electricity, an essential resource of modern society that we can often encounter in our daily lives. However, people often have a hard time grasping what can be done when electricity and engineering meet.
It used to be called the Department of Electrical Engineering, but recently it has been changed to the Department of Electrical and Computer Engineering. Why did they change the name to something that has nothing to do with electricity and information? There may have been many reasons for the name change, but I would like to explain what kind of research is done at the Department of Electrical Engineering through the reasons I think there are.
In electrical engineering, “electricity” can be broadly divided into electricity as energy and electricity as signals. I am particularly interested in the field of electricity as signals, and this technology has advanced to the point where it has a significant impact on other industries. It is even applied to the field of electrical energy. To explain the field of electrical energy, it is easy to understand if you think of energy as the source of power that moves objects.
As we know, electricity is produced at power plants and transmitted to various parts of the country, and is used to operate various devices. Therefore, people majoring in electrical energy study how to efficiently produce electricity, how to store this energy source, and how to reduce electricity loss and transmit it cheaply.
Electric energy is more organized than other energy sources, such as thermal energy, so it has a low loss rate even when transmitted over long distances, and is suitable for conversion into other forms of energy. As such, electric energy is suitable for handling the vast amount of energy used by humanity, so it is impossible to imagine living without electricity in modern society, and all of this can be attributed to the achievements 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, let’s look at the definition of a signal. In electrical engineering, a signal can be defined as a physical quantity that conveys information. In particular, it refers to voltage that conveys information among various physical quantities such as temperature, speed, sound, and pressure. There is the field of signal processing, which efficiently receives signals and processes them in a way that we can understand, and there is also the field of communication, which deals with devices such as radios and telephones that send and receive these signals. It is literally a discipline that deals with signals themselves.
We need more sophisticated technology to use these technologies easily anytime, anywhere. There is a field of circuits that creates circuits that amplify and store signals that have been sent to a distant location via communication and have been reduced in size, and there is also a semiconductor field that creates semiconductor devices that make up those circuits. There is also a field of electrophysics and devices that creates devices that can convert processed signals into images. Finally, there is a system field that enables the systems of these devices to operate stably, and there is also a computer field that processes the information contained in signals. Therefore, electricity as a signal is not just a simple voltage, but rather valuable information that must be handled with great care.
Recently, the field of electrical engineering has become even broader, and it would take a lot of space to introduce the detailed fields. This time, I will explain the electrical engineering technology applied to MRI. MRI is an aggregate of electrical engineering technologies. Basically, MRI requires a powerful electromagnet. You probably remember making an electromagnet in elementary school science class and seeing patterns drawn to it when placed near iron filings. The electromagnets built into MRIs are much more powerful than those in elementary school science class, so you probably know that you can’t bring metal objects into an MRI scan.
These powerful electromagnets align the water molecules in our bodies in the direction of the electromagnet’s magnetic field. In fact, we don’t feel it very much, but more than 90% of all forces in the universe are electromagnetic forces. Electromagnetic forces are usually in equilibrium, making it difficult for humans to feel them. However, when this equilibrium is broken, phenomena such as static electricity and lightning occur. Returning to the MRI, when water molecules in equilibrium are exposed to electromagnetic waves of a certain frequency, they begin to vibrate. This is similar to the resonance effect that produces a specific sound when a string is plucked. That is why MRI is called “Magnetic Resonance Imaging.”
When stimulated, water molecules vibrate and emit electromagnetic waves of a specific frequency, and the strength of the emitted electromagnetic waves varies depending on the water density of the tissue in the body. This principle allows the receiver to receive signals, estimate the shape of the tissues in the body, and convert them into images that can be read by the doctor. In the early days of MRI, it took a long time to obtain signals, which caused patients to suffer from claustrophobia.
At first, electrical engineers who specialized in signal processing were involved in MRI research to reduce patient discomfort and to quickly image more patients. As a result, images with no significant difference from the original image could be obtained with much less signal than before. Recently, MRI technology has advanced to the point where the movement of the heart can be checked in real time. This technology plays a major role in dramatically processing biological information.
In this way, electrical engineering is not only about electronic devices that are already deeply ingrained in our lives, but also about medicine, 3D imaging, information processing, and artificial intelligence. It is expanding into areas that we cannot even imagine under the name of electricity. In the future, electrical engineering will develop beyond simple signal processing to a field in which computers process signals more intelligently.
