Nanotechnology is the manipulation of matter at the scale of a billionth of a meter to create new properties. It holds the promise of solving problems in energy, environment, healthcare, and more, and is rapidly advancing from a bottom-up and top-down approach to nanodevices, MEMS technology, biochips, and biomimetics.
The phrase “Micro air bubbles break down dirt and make it clean!” is often used in washing machine advertisements. As long ago as April 2012, the Environmental Mechanical Systems Laboratory at the Korea Institute of Mechanical Engineering announced that it had developed the original technology to uniformly generate up to one ton of nano air bubbles per minute with 40% less energy than conventional methods. The nano- and micro-sized bubbles are almost unaffected by buoyancy and can be maintained deep in the water for about three months, creating a rich oxygen environment that helps various bacteria to multiply smoothly. These bacteria are then able to break down pollutants and purify the water. We often hear about the use of “microscopic things” or nanotechnology across industries. There are some technologies that are so small that they can dramatically change the world, and nanotechnology is one of them.
The term nanotechnology refers to the creation and manipulation of objects at the nanometer level. A nanometer is a billionth of a meter, and it’s about the length of three or four metal atoms. At its core, nanotechnology is about manipulating matter at the atomic or molecular level to create devices or systems with entirely new properties and functions. This is why nanotechnology has become so popular in recent years, as it transforms existing materials into innovative materials with new properties. Nanotechnology is a bridge to overcome various problems and limitations of existing technologies. In the 21st century, these challenges include hunger due to population explosion, environmental pollution, energy and resource depletion, and incurable diseases such as cancer. In the industrial sector, we are facing the limitations of miniaturization of semiconductors. However, nanotechnology offers limitless possibilities for materials, transforming human imagination into reality. Nanotechnology has been actively researched for the past 20 years, breaking down boundaries between disciplines and combining with life, energy, environment, and IT technologies, and has reached the stage of industrialization and commoditization. However, nanotechnology is still a young field, only about 30 years old. Let’s take a look at how nanotechnology has evolved to where it is today.
Although there are examples of nanotechnology being utilized in ancient and medieval times, this article will focus on the development of nanotechnology alongside modern theories. The man who started the modern era of nanotechnology was Nobel Prize winner Richard Feynman. In 1959, he gave a lecture to the American Physical Society titled “There’s a Lot of Space at the Bottom”. Feynman proposed that if we could manipulate matter at a very small level, like the atom, we could harness its limitless properties. Although many people at the time dismissed his ideas as far-fetched, he was convinced of the advent of nanotechnology and believed that in the future we would be able to manipulate matter in any way we wanted at the atomic level. Another person who actively promoted nanotechnology to scientists and politicians and led the revival was nanotechnology theorist Kim Eric Drexler. He realized the importance of nanotechnology and emphasized its potential through his writings and exchanges.
Then, in 1981, Dr. Gerd Binnig invented the scanning tunneling microscope (STM), which allows observation down to the atomic level. Based on quantum mechanical principles, this instrument can observe and modify the surface structure of semiconductor or conductor materials at the nanometer level. The invention of the STM made the world of atoms and molecules not only observable, but manipulable. In 1990, IBM’s Dr. Donald Eigler used an STM to create the letters “IBM” by moving 35 xenon atoms at ultra-low temperatures on a nickel metal surface. This was a symbolic demonstration of the ability to record information using atoms, and the invention of the tool helped catapult nanotechnology research into high gear.
In 2000, national support for nanotechnology began. The U.S. government launched the National Nanotechnology Initiative (NNI) and allocated $490 million to nanotechnology research. This sparked a global nanotechnology race, and the technology has evolved to where it is today.
Let’s take a look at how scientists have approached the nanoscale world and explore some of the most prominent technologies and recent research achievements. Scientists have used both bottom-up and top-down approaches to approach the nanometer realm. The bottom-up approach involves assembling atoms or molecules one by one to create the desired structure. The top-down approach, on the other hand, involves slicing and dicing larger materials to create nanometer-scale devices and materials, a method that has been used since the Stone Age.
A prime example of a top-down approach is micro-electro-mechanical systems (MEMS) technology. MEMS is a microelectronic control technology that uses semiconductor process technology to create ultra-compact, precision machines at the micro or millimeter scale. These products, which are smaller than the width of a human hair, are not visible to the naked eye and must be operated entirely through a computer screen. The principle of MEMS technology is that chemicals mark where to place certain materials on a thin silicon wafer, and unnecessary parts are removed to form circuits. Many products are being developed using MEMS technology, such as inkjet printers that can produce crisp prints, nanotechnology pipes that accurately administer medication, and medical devices that can move paralyzed limbs.
There are several challenges to advancing MEMS technology. It requires overcoming physical phenomena and inertia that only occur in the nanoscale world, and it requires processing techniques that find the right material without destroying it. Semiconductor technology using MEMS has now enabled the manufacture of thumb-sized USBs with a capacity of 1 terabyte.
Nano-biomimetics is also gaining traction. This is the application of biological nanotechnology to real-life applications, such as adhesive pads that mimic the soles of gecko lizards. The microscopic cilia on the soles of the gecko’s feet provide strong adhesion using intermolecular attraction, which Seoul National University researchers mimicked to develop an adhesive pad that can be used permanently without adhesives. Other applications of nanobiomimetics are endless, such as using the skin structure of dolphins to create barnacle-free boat bottoms, or mimicking the surface of lotus leaves to develop eco-friendly, water-resistant paints.
The bottom-up approach, which builds atoms one by one, is currently limited to the formation of simple letters, but in the future could lead to the creation of nanomachines. Bionanotechnology combines bottom-up and top-down approaches to develop new biomaterials and devices by analyzing and processing DNA, RNA, and other nano-sized biomolecules that make up the human body at the molecular level. A typical application of bionanotechnology is biochips. Biochips integrate biological components onto a silicon substrate and have led to the development of artificial organs that mimic the liver, neurons, and capillaries.
Bionanotechnology is also of great interest for nanorobotics research. With the development of biofuel cells and photosynthesis-based technologies, the time is coming when nanorobots will be able to enter blood vessels, destroy the cause of disease, adsorb radioactive materials, and discharge them without harming the body.
Beyond this, nanotechnology is showing us possibilities that transcend the limits of physical laws and common sense.
