This blog post explores how small yet powerful nanotechnology can address challenges humanity faces in areas like the environment, energy, and medicine.
“Micro air bubbles break down pollutants to clean!” is a phrase often used in washing machine advertisements. Long ago, in April 2012, the Environmental Machinery Systems Research Laboratory at the Korea Institute of Machinery and Materials announced the development of a core technology that uniformly generates up to one ton of nano air bubbles per minute using 40% less energy than existing methods. Nano- and micro-sized bubbles are minimally affected by buoyancy, allowing them to remain submerged for approximately three months. They create an oxygen-rich environment, facilitating the smooth proliferation of various bacteria. These bacteria accelerate pollutant decomposition, achieving water purification effects. We frequently encounter stories in the media about how ‘tiny things’—namely, nanotechnology—are being used across industries. The smaller the size, the more revolutionary the technology can be—let’s examine this nanotechnology.
Nanotechnology is a general term for creating and manipulating objects at the nanometer level. A nanometer is one billionth of a meter, roughly the length of three or four metal atoms lined up. The core of nanotechnology lies in manipulating materials at the atomic or molecular level to create devices or systems with entirely new properties and functions. This is why nanotechnology is currently in the spotlight—it transforms conventional materials into innovative ones with novel properties. Nanotechnology is serving as a bridge to overcome various problems and the limitations of existing technologies. Major challenges in the 21st century include hunger caused by population explosion, environmental pollution, depletion of energy and resources, and incurable diseases like cancer. In the industrial sector, the miniaturization of semiconductors has reached its limits. However, nanotechnology presents the infinite potential of materials and is transforming human imagination into reality. Currently, nanotechnology breaks down disciplinary boundaries, combining with life sciences, energy, environmental science, and IT technologies. It has been actively researched over the past 20 years and has reached the stage of industrialization and commercialization. Yet, despite leading the scientific community, nanotechnology is a relatively new field, having emerged only about 30 years ago. Let us now examine how nanotechnology has developed to reach its current state.
While there are examples of nanotechnology being utilized in ancient and medieval times, this article will focus on nanotechnology as it has developed alongside modern theory. The figure who opened the curtain on modern nanotechnology was Nobel Prize in Physics laureate Richard Feynman. In 1959, he delivered a lecture titled “There’s Plenty of Room at the Bottom” at the American Physical Society. Feynman proposed that if we could manipulate matter at the atomic level, we could harness its infinite properties. While many dismissed this as absurd at the time, he was convinced of nanotechnology’s arrival, believing we would one day manipulate matter at the atomic level as we wished. The figure who actively promoted nanotechnology to scientists and politicians, driving its resurgence, was the nanotechnology theorist Kim Eric Drexler. Recognizing the importance of nanotechnology, he emphasized its potential through his writing and networking.
Then, in 1981, Dr. Gerd Binnig invented the scanning tunneling microscope (STM), capable of observing down to the atomic level. This device, based on quantum mechanical principles, could observe and modify the surface structure of semiconductors or conductive materials at the nanometer level. The invention of the STM made the world of atoms and molecules not only observable but also manipulable. In 1990, Dr. Donald Eigler of IBM used an STM to move 35 xenon atoms on a nickel metal surface at cryogenic temperatures to form the letters ‘IBM’. This became a symbolic demonstration of the potential to record information using atoms, and the invention of this tool became a catalyst for the full-scale advancement of nanotechnology research.
By the year 2000, national support for nanotechnology began. The U.S. government launched the National Nanotechnology Initiative (NNI) plan, investing $490 million in nanotechnology research. This marked the start of a global nanotechnology competition, driving continuous technological advancement to the present day.
Now, let’s explore how scientists have approached the nanoworld and examine representative technologies and recent research achievements. Scientists have employed both bottom-up and top-down approaches to access the nanometer realm. The bottom-up approach involves assembling atoms or molecules one by one to create desired structures. Conversely, the top-down approach carves and shapes larger materials to produce nanometer-scale devices and materials, a method used since the Stone Age.
A prime example of the top-down approach is MEMS (Micro-Electro-Mechanical Systems) technology. MEMS, a micro-electromechanical control technology, utilizes semiconductor process technology to fabricate ultra-small precision machines at the micro- or millimeter scale. These products, smaller than a strand of hair, are invisible to the naked eye, necessitating all operations to be performed via computer screens. The principle of MEMS technology involves chemically marking the positions for specific materials on a thin silicon wafer, then removing unnecessary parts to form circuits. MEMS technology has enabled the development of numerous products, such as inkjet printers capable of sharp printing, nanotechnology pipes for precise drug delivery, and medical devices that enable movement of paralyzed limbs.
Several challenges exist in advancing MEMS technology. It must overcome physical phenomena and inertia unique to the nanoscale world, and requires processing techniques to find suitable materials that won’t be destroyed by the target application. MEMS-based semiconductor technology has now enabled the production of thumb-sized USB drives with 1 terabyte capacity.
Nano-bionics is also gaining attention. This is an engineering field applying biological nanotechnology to everyday life. A prime example is adhesive pads modeled after the feet of gecko lizards. The microscopic hairs on a gecko’s feet provide strong adhesion using intermolecular forces. Researchers at Seoul National University mimicked this to develop adhesive pads that can be used permanently without glue. Furthermore, the applications of nano-biomimetic engineering are limitless. Examples include creating ship hulls resistant to barnacle growth by applying dolphin skin structure, or developing eco-friendly water-repellent paint by mimicking lotus leaf surfaces.
The bottom-up approach involves assembling atoms one by one. While currently limited to forming simple characters, it is expected to enable the fabrication of nanoscale machines in the future. Bionano technology combines bottom-up and top-down approaches to analyze and process nano-sized biomolecules like DNA and RNA that compose the human body at the molecular level, developing new biomaterials and devices. A prime application of bionano is the biochip. Biochips are products integrating biological components onto silicon substrates, and have now advanced to the development of artificial organs mimicking the liver, neurons, and capillaries.
Furthermore, bionano technology is also focusing significant attention on nanorobot research. With the development of biofuel cells and photosynthesis-based technologies, an era is approaching where nanorobots can travel through blood vessels to destroy the causes of disease and adsorb radioactive materials, expelling them in a state harmless to the human body.
Beyond this, nanotechnology is showing us possibilities that transcend the limits of physical laws and common sense.
