What are the modern theories of nanotechnology? How did nanotechnology evolve?

In this blog post, we’ll take a look at nanotechnology.

 

“Microscopic air bubbles break down dirt and make it clean!” This phrase is often used in washing machine advertisements. As long ago as April 2012, the Environmental Mechanical Systems Laboratory at the Korea Advanced 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 remain deep in the water for up to about three months, creating a rich oxygen environment in the water that allows various types of bacteria to multiply smoothly. These bacteria are said to accelerate the breakdown of pollutants, resulting in water purification. Like this example, we’ve been hearing a lot in the media lately about the use of “microscopic” things, or nanotechnology, across industries. But there are some technologies that are so small that they can change the world forever. Let’s take a look at nanotechnology.
Nanotechnology refers to the creation and manipulation of objects at the nanometer level. A nanometer is a billionth of a meter and is about the length of three or four metal atoms. At its core, nanotechnology is about manipulating and creating materials at the atomic or molecular level to create devices or systems with completely new properties and functions. This is why nanotechnology has become so popular in recent years. It transforms existing materials into new and innovative ones. It’s a bridge to overcome many problems and limitations of existing technologies. Some of the major ills of the 21st century include hunger due to population explosion, the environment, pollution, energy and resource depletion, and terminal diseases such as cancer. In addition, industry has always faced a limit to the miniaturization of semiconductors. However, nanotechnology continues to offer infinite possibilities of materials, transforming human imagination into reality. Today, nanotechnology is being researched more than any other field in the last two decades, combining life, energy, environment, and IT technologies across disciplinary boundaries. Nanotechnologies that were in the lab a decade ago are now being industrialized and commercialized, such as nano-sterilization products. Surprisingly, however, the technology that’s taking the scientific world by storm is only about 30 years old. Let’s take a look at how nanotechnology has come so far in such a short period of time. There are examples of nanotechnology being used in ancient times and even in the Middle Ages. However, in this article, we’ll be talking about nanotechnology with its modern theories.
The man who started the modern era of nanotechnology was Richard Feynman, a Nobel Prize winner in physics. In 1959, he gave a lecture at the American Physical Society titled “There’s Plenty of Space at the Bottom”. He proposed that if we could manipulate matter at a very small level, such as the atom, we could harness the infinite properties of matter. While many people dismissed this as far-fetched, he confidently predicted the advent of nanotechnology and believed that in the future we would be able to manipulate atoms in any way we wanted. Another person who was instrumental in the revival of nanotechnology by actively promoting it to scientists and politicians was Kim Eric Drexler, a nanotechnology theorist. He realized the importance of nanotechnology and advocated its potential through his writings and interactions with politicians and scientists.
Then, in 1981, Dr. Gerd Binnig invented the scanning tunneling microscope (STM), which allows observation down to the atomic level. This instrument is based on quantum mechanical principles and can observe or modify the structure of the surface of semiconductor or conductor materials at the nanometer level. This extraordinary microscope transformed the world of atoms and molecules, which we had previously recognized only as abstract concepts, into a world that could be observed and manipulated. The significance of these microscopes is that they can not only observe atoms, but also manipulate them, meaning that they can be dragged or lifted, and chemical reactions can be triggered. Scanning tunneling microscopes are therefore a window into the atomic world. In 1990, Dr. Eigler used an STM to create the letters IBM by moving 35 xenon atoms at ultra-low temperatures on a nickel metal surface. This symbolically demonstrated that atoms could be used to memorize information. With the invention of this tool, scientists began to study nanotechnology in earnest.
In the year 2000, national support for nanotechnology began. The U.S. government launched the National Nanotechnology Initiative (NNI) and poured $490 million into nanotechnology research. From there, the race to nanotechnology was on for the rest of the world. It has continued to evolve, leading to modern nanotechnology.
Let’s take a look at how scientists have approached the unknown world of nanotechnology, its main technologies, and recent research achievements. Scientists have used two main methods to approach the realm of nanometers. These are the bottom-up and top-down approaches. The bottom-up approach involves assembling atoms or molecules one by one to create the desired machine. The top-down approach, on the other hand, has been used since the Stone Age to create materials and devices in the nanometer range by shaving and refining large materials.
Let’s take a look at MEMS technology as an example of the top-down approach. MEMS, also known as microelectromechanical control technology, is a technology that creates ultra-small precision machines in the micro or millimeter size based on semiconductor process technology. To make products smaller than the thickness of a human hair, you can’t see or touch them, so you have to watch everything on a computer screen. Let’s take a quick look at how MEMS works. On a wafer, a thin circuit board of silicon crystals, which is the basis of MEMS technology, light-sensitive chemicals mark where certain materials are to be placed according to a computer-automated blueprint. The wafer then accepts only certain liquids and corrodes or removes unwanted parts that are placed in unwanted places. MEMS machines are built up layer by layer in this way. In this way, an ultra-microscopic machine is created by coating a material, removing some of it, building another layer on top of it, and connecting it to the previous layer. In fact, Sandia National Laboratories has succeeded in creating an ultra-microscopic cog with a size of 0.2 millimeters, smaller than a tick. Many products are expected to be developed using this mems technology. For example, inkjet printers that can be stored for long periods of time without hardening and print more clearly, nanotechnology pipes that deliver medicine quickly and safely without discomfort to patients, and medical devices that can move paralyzed limbs.
In fact, several innovations are needed to advance mEMS technology. In addition, there are still challenges to be solved in the development of not only mesoscopic devices, but also in the development of mesoscopic materials. The membranes need to be made differently depending on the object and not destroyed while performing their tasks. It also needs to be processed by finding the right materials. In addition, the stability of MEMS machines, which will be invaluable in medicine, is of utmost importance, and scientists are actively working on it. Semiconductor technology using MEMS has already been used to create a thumb-sized USB with a capacity of 1 terabyte.
Nanobiomimetics based on nanotechnology is very popular. Nanobiomimetics is the application of nanotechnology hidden in living organisms. Biomimicry is actually an efficient way to get great ideas, and there is a lot of biomimicry research going on. A classic example is the gecko lizard’s sole. If you look at the sole of a gecko’s foot, there are tons of microscopic cilia. The intermolecular attraction of these microvilli creates a strong adhesive force, allowing the gecko to stick to smooth glass walls and ceilings. In 2009, Professor Gap Yang Seo of Seoul National University and Professor Sang-Seok Moon of the Department of Chemical and Biomolecular Engineering invented an adhesive pad that mimics the sole of a gecko’s foot. It does not require any adhesive or water for adhesion, and it sticks in a specific direction, making it easy to remove. It is also expected to be very useful in hospitals and industries as it can be used permanently because it utilizes intermolecular attraction.
Other applications of nanobiomimetics include the use of bumps on the surface of dolphins to create a barnacle-free underbelly, or the imitation of microscopic bumps on lotus petals to create eco-friendly, waterproof paints that don’t get wet and don’t stain, so there’s plenty of scope for future research.
Next, let’s look at the bottom-up approach. The bottom-up approach involves assembling atoms one by one, and humans are currently too poorly equipped to assemble atoms or molecules directly to create nanomachines that perform the desired function. While we can move atoms with conventional STMs, it’s still a pipe dream to assemble atoms to create a nanomachine, let alone write the alphabet. The prevailing opinion is that nanomachines should be protein machines with many different functions. However, there are many difficulties in designing and manufacturing even a simple protein. This is because it is impossible to calculate the interatomic bonds and predict what the resulting protein will do. So scientists have turned to borrowing from living organisms to carry out this complex design and manufacturing process. The combination of this bottom-up approach and the typical top-down approach of MEMS technology is called bionanotechnology.
Bionano technology studies nano-sized biomolecules such as DNA, RNA, and protein cells that make up the human body, analyzes them at the molecular level, and enables the development of biomaterials and devices with new biological, chemical, and physical properties through artificial processing and control. A very promising area of bionanotechnology is the field of biochips. Biochips are products that integrate biological materials, such as various components of an organism’s body that have been artificially processed into microscopic electronic circuits on a silicon substrate. The field of biochips is currently mimicking livers, neurons, and capillaries. It is expected that many artificial organs will be developed using biochips in the future.
Bionanotechnologists are also very interested in creating nanorobots. In fact, biofuel cells are being developed, photosynthesis, protein motors, etc. are being developed, and the development of nanorobots is getting closer and closer to reality. We may soon have microscopic robots running through our veins and curing diseases. The goal of bionanotechnology is to cure incurable diseases or develop environmentally friendly resources and energy through nanoscale biomedicine. In fact, a 2012 report from the Center for Biotechnology Policy Research predicts that practical nanorobots will be built and commercialized by 2025.
As we’ve seen, nanotechnology knows no disciplinary boundaries, its scope is vast, and its potential is still untapped. Some people point out the dangers of artificial intelligence and biological and chemical weapons that will emerge from nanotechnology. However, the risks are being emphasized and theoretical countermeasures are being developed, making nanotechnology one of the most active fields of research in laboratories around the world. The 21st century is the world of nanotechnology. If you look at the lab bulletin boards in the mechanical and aerospace engineering department building at my school, it’s all about nano. Two or three years ago, it was expected that the level of nanofabrication would not exceed 10 nm, but less than a year later, the 10 nm barrier has been broken. At this rate of growth, it’s easy to imagine that the cute nanorobots we’ve seen in CG movies might actually be able to enter our bodies and repair broken cells. As someone once said. “The limits of nanotechnology are the limits of human imagination!”