In this blog post, we will take a natural look at the concept, development, core principles, applications, and limitations of nanotechnology, while staying true to the original text.
Nanotechnology is one of the key fields representing modern science and technology. Today’s science and technology can be broadly categorized into nanotechnology, biotechnology, and information technology, and among these, nanotechnology is receiving particular attention. In the past, placing iron atoms one by one on a copper plate to engrave the character “原字” was considered cutting-edge technology, but today, various research projects are underway to directly control and utilize atoms and molecules. Underlying these scientific and technological innovations were advances in the science of understanding atomic structure and the technology for manipulating atoms. In 1913, Niels Bohr made a significant contribution to explaining atomic structure by proposing the atomic model, and it was later discovered that the size of an atom is approximately 0.1 nanometers. In 1959, Richard Feynman proposed the idea that technology capable of directly manipulating atoms might be possible, and later, Eric Drexler defined nanotechnology as “the technology of controlling and manipulating matter at the nanometer scale,” bringing it to widespread attention. In 2000, the United States announced the National Nanotechnology Initiative (NNI), establishing nanotechnology as a key research field at the national level; today, countries around the world are competitively pursuing research and development in this field.
“Nano” is a prefix in the International System of Units (SI) meaning one-billionth. One nanometer (nm) is approximately the length of 10 atoms, about one-hundredth the size of a cell, and about one-seventy-thousandth the thickness of a human hair. Generally, nanotechnology refers to the technology of creating new materials, components, and systems using nanometer-scale materials. The U.S. National Nanotechnology Initiative (NNI) defines nanotechnology as technology that deals with materials in the range of 1 to 100 nanometers. This criterion was established because when the size of a material shrinks to 100 nanometers or less, quantum effects become prominent, resulting in physical and chemical properties that are entirely different from those of larger-scale materials. For example, while ordinary gold is yellow, gold particles measuring just a few nanometers in size exhibit different characteristics, such as red or purple hues. Nanotechnology has developed not only from basic sciences such as biology, physics, and chemistry but also based on atomic processing and atomic measurement technologies, and is currently being utilized in various fields of science and technology.
The concept of nanotechnology was first introduced at a meeting of the American Physical Society held at the California Institute of Technology (Caltech). Until then, the prevailing view was that it was impossible to artificially control atoms or molecules. However, in 1959, Richard Feynman presented the possibility of future technologies that directly manipulate atoms in his famous lecture titled “There’s Plenty of Room at the Bottom.” He predicted that in the future, the vast collection of a library could be stored in a space no larger than a speck of dust, and that microscopes capable of directly observing atoms would be developed.
About 20 years after Feynman’s lecture, his predictions became reality. In 1981, Gerd Binnig and Heinrich Rohrer at the IBM Research Laboratory in Switzerland succeeded in developing the scanning tunneling microscope (STM). This instrument enabled the observation of surface structures at the atomic level by bringing an extremely fine probe made of platinum or tungsten very close to the surface of a sample and measuring the resulting changes in the tunneling current. Subsequently, as technologies for moving individual atoms were developed using this principle, nanotechnology entered a phase of full-scale advancement.
Nanotechnology became widely known to the general public starting in the 1980s. In 1986, Eric Drexler published ‘Engine of Creation: The Coming Era of Nanotechnology’, outlining the future of nanotechnology. This book served as a catalyst for popularizing the term “nanotechnology” and envisioned a future in which nanorobots would remove atherosclerosis from blood vessels or selectively treat cancer cells. Even today, various research efforts continue to bring these concepts to fruition. At the same time, he warned of the ethical issues surrounding nanotechnology, raising the possibility that self-replicating nanomachines could pose serious risks if they got out of control.
Nanomaterials are primarily produced through top-down and bottom-up technologies. Top-down technology involves gradually processing existing large materials into smaller pieces to create structures of the desired size. This process is similar to carving a stone to create a lithograph. A prime example is the semiconductor manufacturing process used to produce integrated circuits on silicon wafers. This method applies lithography technology—used in photographic processes—to expose the silicon wafer to an electron beam and remove unnecessary parts. Advances in these top-down technologies have led to steady improvements in semiconductor integration density, and today, cutting-edge semiconductor processes at the nanometer scale have been commercialized.
In contrast, bottom-up technology is similar to the process of stacking LEGO blocks one by one on an empty desk. The atomic force microscope (AFM) is a prime example of equipment that utilizes this bottom-up technology; it was developed based on the principles of the scanning tunneling microscope. When a probe is brought within nanometers of a sample’s surface, forces acting between atoms are generated; these forces can be used to move atoms one by one or position them at desired locations. Because this method involves assembling atoms one at a time, it takes a significant amount of time even to create a single molecule measuring tens of nanometers. However, since top-down technology alone has limitations in fabricating extremely small structures, bottom-up technology plays a crucial role in complementing it.
The reason for conducting nanotechnology research using such complex and precise equipment is that it allows us to overcome the limitations of existing technologies. The advantages of nanotechnology lie primarily in the ability to utilize both the physical and chemical effects resulting from minute sizes and the quantum effects that manifest at the nanoscale. First, the physical effects stem from the phenomenon where the surface area increases relatively as the size of a particle decreases. As the surface area increases, reaction rates accelerate and absorption rates rise. Furthermore, the more uniform the particle size, the more consistent the reaction can be maintained, and mixing becomes easier. These characteristics have long been utilized in industries such as food and cosmetics, and today, the physical properties of nanoparticles are actively being applied in various fields, including information technology and medical technology.
In the field of information technology, radio-frequency identification (RFID) technology is a prime example of this application. RFID is a system that uses integrated circuits to wirelessly recognize and manage information about various objects. It can be manufactured by attaching radio-frequency identification devices to flexible plastic films and has garnered attention as a technology capable of replacing traditional barcodes. As nanotechnology advances, the possibility has emerged that RFID devices could be miniaturized to sizes nearly invisible to the naked eye, and related technologies are steadily evolving. However, these technologies are also sparking new social debates regarding privacy concerns and the potential for data breaches.
Nanotechnology is also being actively researched in the field of medical technology. In particular, nanotechnology for cancer treatment remains one of the most important areas of research today. Among these, a substance that has attracted significant attention is fullerene. Fullerene is a molecule composed of 60 carbon atoms bonded in a soccer-ball-like shape; it was discovered in 1985 and is also called a “buckyball” due to its unique structure. Fullerene has a highly stable structure, allowing it to maintain its shape even under high temperatures and pressures. By leveraging these properties, fullerenes have the potential to be used as drug delivery vehicles that encapsulate drugs and deliver them to specific tissues. If they can transport therapeutics that selectively target only cancer cells, this is expected to help reduce the problem of conventional cancer treatments damaging healthy tissue as well, and various studies are currently underway.
Another important advantage of nanotechnology is the ability to harness quantum effects that occur at the nanoscale. Unlike the macroscopic world we experience in daily life, the nanoworld exhibits various quantum mechanical phenomena. Electrons can exhibit the tunneling effect, passing through extremely thin barriers, and the state of particles is described probabilistically. These quantum properties enable a different mode of computation from conventional logic operations, and based on this, various next-generation information technologies, including quantum computers, are being researched. In addition, research utilizing quantum effects is actively underway in various fields, such as information technology and materials engineering.
In the field of information technology, research is also being conducted to develop single-electron transistors (SETs). While conventional transistors require a large number of electrons to control current, SET technology explores the possibility of a single electron acting as a switch. Since electrons move one at a time, quantum effects play a significant role, and research continues to realize next-generation devices that operate at very low power by utilizing these effects. Professor Hong-Geun Park’s research on single-molecule transistors at Harvard University in 2000 garnered worldwide attention, and related research has continued to advance steadily since then. However, the prospects for commercialization suggested at that time have not yet been fully realized, and active research is still ongoing.
In the field of materials science, carbon nanotubes—which possess exceptional strength and thermal conductivity—are a representative nanomaterial. Discovered by Sumio Iijima in 1991, carbon nanotubes are materials formed by hexagonal carbon structures linked in a cylindrical shape. Although they are composed of carbon, just like graphite or diamond, they possess high strength and excellent electrical and thermal properties, making them useful in a wide range of industrial fields. Currently, research and commercialization are underway in various fields, including batteries, composite materials, electronic devices, sensors, and energy storage devices, and they are also being utilized in various technologies that handle nanoscale materials.
While various nanotechnology research projects are underway to enrich our lives, concerns about nanotechnology are also being consistently raised. Past surveys have shown that while the number of people interested in nanotechnology is increasing, some respondents perceive that the risks posed by nanotechnology may outweigh its benefits. Furthermore, some civic groups and experts have pointed out that nanotechnology could lead to unforeseen risks if used without sufficient safety verification. In particular, computer scientist Bill Joy warned of the potential dangers of nanotechnology by proposing the so-called “Grey Goo” scenario, in which self-replicating nanomachines could spiral out of control and have a serious impact on the ecosystem.
Some environmental groups have also raised concerns that nanoparticles could pose risks similar to those of the next-generation asbestos. In fact, various studies are underway to assess the biocotoxicity and environmental impact of nanoparticles, and research findings have indicated that some nanomaterials may exhibit toxicity depending on exposure conditions and concentration. However, these results were obtained from specific materials under specific experimental conditions, and it cannot be generalized that all nanomaterials pose the same level of risk. Therefore, research is currently ongoing to establish safety assessment and risk management systems tailored to individual nanomaterials.
While nanotechnology holds the potential to significantly improve human life—through applications such as cancer treatment and the development of new materials—it also carries the potential to create new environmental and health challenges. In this regard, technological advancement and safety assurance must go hand in hand. Sociologist Ulrich Beck has argued that while it is not advisable to halt all nanotechnology research, institutional mechanisms are necessary to appropriately regulate the technology when there is a possibility that it could cause serious side effects or ethical issues. Furthermore, sociologist of technology Michel Calong emphasized that not only scientists and engineers but also citizens must actively participate in discussions regarding nanotechnology. He argued that the process by which diverse stakeholders engage in informed debate and reach a social consensus is the most crucial method for resolving the issues associated with nanotechnology.
While science and technology are key drivers of progress in human life, neither unconditional trust nor unfounded anxiety is a desirable attitude. Nanotechnology, too, must be evaluated in terms of both its benefits and risks based on objective research findings; only when social discourse is grounded in accurate information—rather than exaggerated expectations or excessive fear—can it truly provide greater value to humanity.
