In this blog post, we will examine the definition, history, key characteristics, applications, limitations, and future prospects of nanotechnology, while proofreading and editing the text to preserve the original content and logic as much as possible.
The 21st century can be described as the era of nanotechnology. From everyday consumer products such as nano-cleaning devices and nano-cosmetics to cutting-edge devices like memory semiconductors manufactured using nanometer-scale processes, nanotechnology is widely utilized across all aspects of our daily lives. Furthermore, nanotechnology is garnering attention as a key technology capable of solving the environmental, health, and energy challenges facing humanity, attracting the interest of many scientists. In the United States, nanotechnology has been designated as one of the key national strategic technologies of the 21st century, alongside the Internet and biotechnology, and the government has continuously supported research and development through the National Nanotechnology Initiative (NNI). Japan and South Korea are also pursuing national policies to foster nanotechnology and are steadily investing in related research. As such, nanotechnology has established itself as a core technology for future society, and given its importance, it is necessary to pay attention to both the significance and the limitations of its development. However, because many people view nanotechnology as the exclusive domain of scientists and engineers, they are often unaware of how far the technology has advanced, what impact it has on society, or what limitations it entails. Therefore, this article will first examine the definition and history of nanotechnology, followed by a sequential review of its characteristics, areas of application, and its drawbacks and limitations.
The term “nano” is derived from the Greek word “nanos,” meaning “dwarf.” One nano represents one-billionth, and one nanometer (nm) is one-billionth of a meter—roughly one-hundred-thousandth the thickness of a human hair and about the size of three or four atoms. Within living organisms, this is comparable to the size of DNA. Since “nano” refers to a unit so small it is difficult to imagine, it is easy to understand that nanotechnology is a technology that deals with the extremely small world. However, there are still various opinions regarding its exact definition. This is because nanotechnology has developed across multiple academic disciplines, and researchers have different approaches. Generally, nanotechnology is known as “the technology of creating new materials by individually controlling atoms or molecules,” and the most widely used definition is “technology that deals with materials ranging in size from 1 to 100 nanometers.” In other words, it can be described as the technology of controlling and manipulating materials at the atomic and molecular levels to create new materials, structures, and devices. Atoms and molecules are the smallest units that make up matter, measuring just a few nanometers in size, while the human eye can only distinguish objects larger than approximately 10,000 nanometers. So how did nanotechnology—which deals with materials invisible to the naked eye—come into being?
On December 29, 1959, in a lecture titled “There’s Plenty of Room at the Bottom” delivered at the California Institute of Technology, Richard Feynman foresaw the era of nanotechnology. Citing the vast amount of genetic information stored within the DNA of a single cell in the human body, he explained that “the entire 24-volume set of the Encyclopædia Britannica could be written on the head of a pin.” Although he ultimately set the goal of freely arranging atoms to create machines at the atomic level, his ideas did not receive much attention at the time because they were considered too revolutionary. However, his lecture is now regarded as the starting point for the development of nanotechnology, and it served as the catalyst for the emergence of films and science fiction works centered on the subject. A prime example is the 1966 film ‘Fantastic Voyage’, which depicts doctors shrunk to nanoscale entering a patient’s bloodstream via a microsubmarine to remove a life-threatening blood clot.
In this way, nanotechnology—which had long existed only in the realm of imagination—came one step closer to reality in 1981 when Gerd Binnig and Heinrich Rohrer developed the scanning tunneling microscope (STM). The STM is a device that scans the surface of an object with an extremely sharp probe, roughly the size of an atom, and converts the obtained information into a computer image—a principle similar to reading Braille with one’s fingertips. By bringing the tip of the probe close to the surface and applying a voltage to measure changes in the current as the probe moves, it is possible to observe the surface at the atomic level. Subsequently, in 1986, the atomic force microscope (AFM), which has a simpler structure, was developed. Unlike the STM, the AFM uses mechanical contact, which has the advantage of allowing observation of insulator surfaces as well. It was later discovered that these instruments could not only observe atoms but also manipulate them directly; in 1990, IBM succeeded in arranging atoms to form the letters “IBM” using an STM. With the development of the scanning tunneling microscope, which enabled the direct observation and manipulation of atoms, nanotechnology entered a phase of full-scale development.
The discovery of fullerenes in 1985 and carbon nanotubes in 1991 marked major turning points in the advancement of nanotechnology. A fullerene is a carbon molecule consisting of 60 carbon atoms arranged in a spherical structure resembling a soccer ball. It has a structure entirely different from that of graphite or diamond—which are also composed of carbon—and because its spherical structure can be modified into various forms and it undergoes active chemical reactions, it has a very wide range of applications. Thanks to these characteristics, fullerenes have attracted significant interest in nanotechnology research.
Carbon nanotubes, discovered six years after fullerenes, also garnered considerable attention. Carbon nanotubes are carbon molecules formed by hexagonal carbon rings linked together to create a cylindrical shape; although their diameter is only about 1 nanometer, their length can reach several hundred nanometers or more. Thanks to this structure, when arranged in bundles, they exhibit tensile strength far superior to that of steel, electrical conductivity superior to that of copper, and thermal conductivity rivaling that of diamond. They are also highly flexible yet resistant to breaking. The discovery of carbon nanotubes, with their outstanding properties, has greatly contributed to the advancement of nanotechnology and, along with the development of the scanning tunneling microscope, has paved the way for the emergence of various nano-based consumer products. Today, not only developed nations but also many other countries view nanotechnology as a future growth engine and are continuously investing in research and development.
The reason for creating nanoscale materials is that as a material shrinks to the nanoscale, the ratio of surface area to volume increases dramatically, causing it to exhibit properties different from those of its macroscopic counterpart. First, at the nanoscale, the color of a material changes depending on the size of the particles. For example, gold (Au) is generally golden in color, but at sizes of approximately 20 nm or smaller, it appears reddish, and even a slight change in particle size causes the color to shift. Second, as a material shrinks to the nanoscale, internal defects decrease, leading to improved strength. Third, as the surface area increases significantly, the chemical properties also change. For example, titanium dioxide (TiO₂) at sizes of approximately 20 nm or smaller exhibits sterilizing effects, self-cleaning capabilities, and anti-fogging properties even when exposed to weak ultraviolet light. Finally, it is known that nanoparticles such as semiconductors undergo significant changes in their magnetic and electronic properties as their size decreases. As such, materials exhibit exceptional properties distinct from their conventional forms at the nanoscale, and research and technological development to apply these characteristics to everyday life are actively underway.
Nanotechnology is currently being utilized in various industrial sectors and can be broadly categorized into the fields of information, energy, and the environment. First, in the field of information technology, nanotechnology has contributed to significantly improving the storage capacity of data storage devices. In the past, IBM developed a data storage device called the “Millipede,” which used an array of numerous nanoscale probes on a silicon chip to create microscopic grooves on the surface and store information in them. This technology presented the possibility of storing far more information than was previously possible. Furthermore, the discovery of carbon nanotubes had a major impact on the development of flat-panel displays with superior performance compared to their predecessors. This is because carbon nanotubes easily emit electrons even at voltages much lower than those of conventional cathode-ray tubes, enabling the production of sharp image quality with minimal power consumption. With the advancement of plastic semiconductor technology, the scope of nanotechnology applications has expanded even further. Although plastics were originally known as insulators that do not conduct electricity, the discovery of electrically conductive polymers has added electrical properties to their existing advantages of flexibility and lightness, bringing them into the spotlight as a new material capable of overcoming the limitations of conventional semiconductors.
Second, nanotechnology is playing a crucial role in solving energy problems. Representative applications include solar cells and fuel cells. Humanity is simultaneously facing the problems of environmental pollution and resource depletion due to the continued use of fossil fuels, and the development of alternative energy sources to address these issues has become a critical challenge. Solar energy is gaining attention as a leading form of renewable energy, and nanotechnology is being researched as one of the core technologies for improving the efficiency of solar cells. In particular, as various new materials utilizing nanostructures are developed, the potential for creating solar cells with higher efficiency than ever before continues to expand.
While solar cells are devices that generate energy, fuel cells are devices that store and utilize the generated energy. Energy storage technology is also crucial for ensuring a stable supply of energy whenever and wherever it is needed. Fuel cells generate electricity through a chemical reaction between hydrogen and oxygen and are regarded as an eco-friendly energy technology because they produce only water as a byproduct. However, hydrogen has the drawback of being difficult to store and transport. To address this, research is underway on high-pressure hydrogen storage technology utilizing high-strength nanomaterials, and carbon nanotubes have also long been the subject of significant interest as a hydrogen storage material.
Finally, nanotechnology plays a crucial role in addressing environmental pollution. First, nanoparticles can be used as sensors to remove pollutants or detect contamination. Since nanoparticles can react effectively with harmful chemicals, they are highly likely to be used to clean up heavily polluted environments. Furthermore, because they can detect even trace amounts of pathogens or harmful substances, they are widely applied in sensor technologies for monitoring environmental pollution. This is why nanotechnology is utilized in various fields, such as water quality testing, food safety inspections, exhaust gas analysis, and toxicity testing of chemicals. In particular, since even trace amounts of toxic substances can have lethal effects on the human body, highly sensitive detection technologies utilizing nanotechnology are of great significance.
Second, to reduce environmental pollution, it is important not only to remove pollutants but also to prevent them from being released into the environment in the first place. Nanotechnology can fulfill this role using nanofiltration membranes. Nanofiltration membranes operate on the principle of selectively filtering out particles larger than their extremely small pores. Zeolite, a representative material, is a porous substance with very small internal pores; it is used to selectively separate or remove various molecules and is widely employed in industrial settings.
While nanotechnology is making a significant contribution to making our lives more convenient in various fields, concerns about nanopollution are also being consistently raised. In 2003, the American Chemical Society published research findings related to the toxicity of carbon nanotubes. The study observed lung damage and inflammatory responses after injecting carbon nanotubes into the lungs of laboratory mice, which significantly heightened concerns about the safety of nanomaterials. This research suggests that nanomaterials could be released into the environment when products containing carbon nanotubes break or degrade, raising concerns about potential contamination of water and air. Based on this, it has been argued that not only carbon nanotubes but also various other nanoparticles could potentially affect the human body. While nanoparticles are highly reactive and can be used to purify the environment by reacting with chemicals, ongoing research is also examining the possibility that they may penetrate deep into the human body and affect organs or tissues. Therefore, as nanotechnology advances and the number of consumer products incorporating nanomaterials continues to grow, research into the safety and environmental impact of nanomaterials must proceed in tandem. For nanotechnology to continue advancing, sustained attention and effort are required not only in technological development but also in establishing safety assessment and management systems.
Currently, nanotechnology has established itself as a foundational technology across various industries, including semiconductors, biotechnology, healthcare, energy, the environment, and information and communications technology, and its scope of application is expanding further through convergence with artificial intelligence, advanced materials, and quantum technology. It is also recognized as one of the key technologies for addressing major global challenges such as water scarcity, energy transition, medical innovation, and eco-friendly industries. To fully realize the potential of nanotechnology in the future, we must maximize the technology’s advantages while continuously reviewing safety and ethical issues. If steady research and development, along with responsible use of the technology, are carried out based on accumulated research achievements and human and physical infrastructure, nanotechnology will play an even more important role as a core technology driving future society.
