A Message to the Younger Generation of Scientists and Engineers

The previous column ended with the summarizing statement that “a scientist must help in the development of human society from the perspective of not only creating civilization, but complementing civilization as well.” This column will again take up the important concept of complementarity while sending a message to the younger generation of scientists and engineers, and finalizing this discussion of MI sensors.

The rights to new technology developments are guaranteed at present by patents, which are intellectual property. Speaking of patent laws that protect patent rights, Abraham Lincoln, an inventor who also served as the 16th president of the United States, was credited with having said the famous words “the patent system adds the fuel of interest to the fire of genius,” a quote inscribed at the entrance of the former US Patent Office. He went on to oversee the end of the American Civil War and he made the decision to make the U.S. an industrialized nation.

From the beginning of 2020, the COVID-19 pandemic has been sweeping the globe. As of September 2021, the time of writing, this 80-year-old author has had his second vaccination against the virus through a priority program for the elderly. And one outcome of this long, invisible pandemic is that pulse oximeters are attracting a lot of attention. This device was actually invented and patented about 50 years ago by a technical development division employee of a certain Japanese company. (Under Japan’s current Patent Act, basic patent rights are valid for a period of 20 years, which means an additional patent rights application is required.) Lightweight and measuring a few square centimeters, this outstanding sensor clips onto the tip of a finger for easy measurement of a person’s blood oxygen saturation. In 2021, local governments around Japan purchased many of these devices to lend to infected residents, in particular those recuperating at home, to measure their own oxygen levels. As a result, purchase by the general public has become difficult. The basic principle is that when hemoglobin binds to oxygen molecules in the blood stream, the color of transmitted light through the blood varies, which can be measured on a transmitted light chromatic spectrum. Actually, this principle is not an application of the technologies of the digital civilization developed in the West, such as the combination of the internet and smartphones that we see nowadays. Rather, optical sensor technologies complement these technologies.

Complementarity itself does not mean increasing the sophistication of applications or technologies. It means using the outcomes of unique science and technology in a way that demonstrates a mutually cooperative relationship between things that exist on different dimensions. This relationship is also evident in the role of electronic compasses in walking navigation services as part of the current internet and smartphone technologies for the digital civilization. In other words, electronic compasses act as geomagnetic sensors to identify directions, which requires high-sensitivity micromagnetic sensors. In the initial stages of development, attempts were made to apply digital technologies by adding computational processing, a digital technology, to low-sensitivity (and low-cost) magnetic sensors. However, this led to longer direction detection times and issues with power consumption due to the computations, so those attempts ended in failure. Amorphous wire MI sensors, which complement digital civilization technologies in smartphones, are becoming increasingly important. At the same time, the presence of high-performance microprocessors as complementary technologies are also increasing. In this way, we can see a multidimensional expansion of science and technology, which are mutually complementary and contribute to the development of humankind.

MI sensors were successfully put to practical use by Aichi Steel Corporation in a collaboration between industry, academia and government in Japan. The company is not only mass producing the sensors for electronic compasses in smartphones, but over recent years, it has also been developing a Global Magnetic Positioning System (GMPS) for autonomous cars, which is one goal of the automotive industry. The GMPS utilizes low-cost, low-magnetism ferrite magnets as magnetic markers embedded in the road surface, together with the ultra-high sensitivity of MI sensors to detect that magnetism, and their ultra-high speed responsiveness based on the magneto-impedance effect and amorphous wire skin effect. In a series of government agency-led verification trials on public roads around Japan, the performance of this system has proven the vehicle’s ability to travel at high speeds and precisely reach its destination in a range of scenarios, including in tunnels and under airport structures where GPS (or GNSS) signals cannot reach. Road surfaces for vehicular traffic include many sources of magnetic noise, including steel beams used to form the roads. In this environment, the remote detection method uses in-vehicle magnetic sensors to detect the weak magnetism of small ferrite magnetic markers embedded at regular intervals in the road surfaces. And this has been achieved through use of the high sensitivity, high-speed responsiveness, and robustness of MI sensor arrays. From the perspective of their complementary use in our modern civilization, it would not be an exaggeration to say that MI sensors are contributing to human society.

At the urging of his third grade teacher at high school, this author aspired to become an electronics scholar, graduating with the first cohort of students from the newly established Department of Electronics and Engineering at a prominent local university. At university and graduate school, he focused on acquiring knowledge of electronic systems, non-biological systems, and immersed himself in research and invention. However, he now regrets not having also acquired the ability to think about biological systems (metabolism, immunization, and genetics).

Applying his life experiences, and from the perspective of dimensionality, his message to the younger generation of science and engineering researchers can be summarized as follows.

It is with great anticipation that this author awaits the day when the younger generation of science and engineering researchers, who are reading this column now, step up to help in the development of human society from the perspectives of both creating and complementing civilization.

2021.11.19