Nanotechnology

Podcast Transcript

In Greek, the word for dwarf is “nanos.”

The International Bureau of Weights and Measures adopted the prefix ‘nano’ to mean one billionth.

A nanometer is one billionth of a meter, and it is the scale at which some of the most groundbreaking work is being done in technology and materials science.

Learn more about nanotechnology, its applications, and how it works on this episode of Everything Everywhere Daily.

It isn’t often that we know exactly when a particular branch of science started, but in the case of nanotechnology, we have a pretty good idea of its precise origin.

The birth of nanotechnology dates back to a presentation given by the Nobel Prize winning physicist Richard Feynman. On December 29, 1959, he gave a presentation to the American Physical Society, which was meeting at Caltech University in California.

The title of his presentation was “There’s Plenty of Room at the Bottom: An Invitation to Enter a New Field of Physics.”

In his presentation, he presented the theoretical idea that we could build machines on a much smaller scale. That if we could manipulate individual atoms, it would have profound implications for the type of things we could create.

Feynman noted that there was no particular reason why we couldn’t make atom-scale machines. It was more a function of engineering than it was physics.

He did note that as things shrank, the challenges involved would be very different than the creation of machines that we are accustomed to in our everyday life.

For starters, gravity would become less and less important the smaller you got. However, other forces, such as the Vander Waahl forces between atoms, would increase considerably.

Feynman had no idea how these new devices could be created, he just knew that there was nothing in the laws of physics which prevented them from being built.

At the end of his presentation, Feynman set down two challenges for anyone to achieve. Each challenge would get a $1000 prize, paid for by himself.

The first challenge was the creation of a tiny motor that would fit into a cube

1/64 of an inch or 0.4 millimeters on each side.

Surprising everyone, that challenge was accomplished in under a year by William McLellan at Caltech. He created a 2000-rpm motor which consisted of 13 separate parts and weighed 250 micrograms.

It wasn’t actually a technical breakthrough. It was more a matter of Fenyman not being aware of the state of the art in miniaturization and engineering.

His second challenge was to scale down written text to be so small that it would be 1/25,000 the size of a printed page. At this level, the entire Encyclopedia Brittanica could be put on the head of a pin.

This proved to be much more challenging than building a small motor.

This prize wasn’t claimed until 1985 when Stanford graduate student Tom Newman managed to print the first page of A Tale of Two Cities on pin head using an electron beam.

Most of the pin head was completely empty as there was more than enough space to write the rest of the book on it.

While writing a book on the head of a pin is interesting, it wasn’t really of practical use.

Beyond being something really small, what exactly is nanotechnology?

As I mentioned in the introduction, a nanometer is a billionth of a meter. To put that into perspective, the width of an average human hair is approximately 100,000 nanometers.

The nanometer scale is the scale of atoms and molecules.

The diameter of a hydrogen atom is 0.06 nanometers. A gold atom is about a third of a nanometer. A water molecule is 0.275 nanometers.

A strand of DNA is 2.5 nanometers in diameter.

Nanotechnology is generally considered to be anything between 1 and 100 nanometers.

As nanotechnology just covers anything really small, it also has applications in a wide range of fields. Nanomaterials, nanoelectronics, and nanomedicine all fall under the banner of nanotechnology, so it is more accurate to call it nanotechnologies.

The first person to use the term nanotechnology was the Japanese researcher Norio Taniguchi in 1971. He used it in reference to the creation of semiconductors.

One of the big technical breakthroughs which allowed for atomic-level analysis was the scanning tunneling microscope. This, for the first time, allowed researchers to view the surfaces of objects at the atomic level.

The development of the Scanning tunneling microscope was awarded the Nobel Prize in Physics in 1986.

Also, in 1986, the first atomic force microscope was developed. The atomic force microscope had a resolution below the nanometer scale. Unlike the previous microscopes, it could do more than just resolve images at the atomic level. It also had the ability to measure forces at the atomic level as well as manipulate individual atoms.

In 1989, Don Engler, an IBM researcher, used an atomic force microscope to manipulate individual atoms. He took 35 xenon atoms and arranged them to form the letters….I…B…M.

To be sure, the manipulation and placement of individual atoms was a huge breakthrough, but spelling IBM with atoms was still just a publicity stunt on a par with writing A Tale of Two Cities on the head of a pin.

Around this time, one of the most important works of nanotechnology was published by an engineer named K. Eric Drexler. The book was titled Engines of Creation: The Coming Era of Nanotechnology.

In the book, he furthered some of the theoretical ideas originally set out by Feynman in his 1959 lecture. In particular, he developed the idea of nano assemblers.

While an atomic force microscope could manipulate atoms, moving individual atoms wasn’t really efficient. When working with technology at the nanoscale, you need to build a lot of whatever it is you’re building.

A single person could never possibly create enough of anything to be of any use, moving one atom at a time.

Drexler’s concept of an assembler would be nanoscale robots that could create nanodevices, including, potentially, copies of themselves.

In theory, such nano assemblers could do….almost anything. In fact, nanotechnology has been the magic wand that many science fiction stories to explain away any sort of advanced technology.

He also addressed a potentially huge theoretical problem with these devices. Self-replicating nano assemblers could replicate unchecked, causing what he called a grey goo scenario.

A grey goo scenario is where uncontrolled nanobots consume all life on Earth as they self-replicate.

As Drexler described it,

Imagine such a replicator floating in a bottle of chemicals, making copies of itself…the first replicator assembles a copy in one thousand seconds, the two replicators then build two more in the next thousand seconds, the four build another four, and the eight build another eight. At the end of ten hours, there are not thirty-six new replicators, but over 68 billion. In less than a day, they would weigh a ton; in less than two days, they would outweigh the Earth; in another four hours, they would exceed the mass of the Sun and all the planets combined?—?if the bottle of chemicals hadn’t run dry long before.

While the odds of such a thing ever happening are close to zero, it is another nightmare doomsday scenario to keep you up at night.

All the theoretical dangers and benefits of nanotechnology aside, what exactly has been done in the world of nanotech?

Most of the current advances in nanotechnology have been in the realm of materials science.

One has to do with the creation of carbon nanotubes. I’ve discussed these before in the episode about carbon, but these are forms of carbon where the carbon atoms are connected to themselves in a sheet that is then rolled up on itself to form a tube.

Nanotubes have incredible properties, but as of today, it is only possible to create them in rather short lengths.

However, there are more than just types of carbon that are created at nanoscales.

Another important nanomaterial are dendrimers.

A dendrimer is a type of synthetic polymer that has a highly branched and three-dimensional structure. The word “dendrimer” comes from the Greek word “dendron,” meaning “tree,” which reflects the branched structure of these molecules.

Dendrimers are typically constructed from a central core molecule, which serves as the “trunk” of the dendrimer. This core is then surrounded by a series of branches, which themselves are subdivided into smaller branches, and so on, resulting in a highly branched, tree-like structure.

Dendrimers have a wide range of potential applications in fields such as drug delivery and gene therapy due to their ability to encapsulate and deliver a variety of molecules, including drugs, imaging agents, and genetic material, to specific targets in the body.

Another nanomaterial are Nanocomposites.

Nanocomposites consist of a nanoscale material that is combined with another, larger material.

The most common nanocomposits are nanoceramic matrix composites, metal matrix composites, and polymer matrix composites.

Depending on the material which is created, they can have a host of useful properties including being stronger, lighter, and more heat resistant.

Quantum dots are also examples of nanotechnology.

A quantum dot is a nanoscale structure made of semiconductor materials that can confine electrons in three dimensions. When the size of a semiconductor material is reduced to a few nanometers, the electrons are forced to exist within a small region of space and exhibit unique quantum mechanical properties.

The size of a quantum dot determines its energy levels and the color of light it emits. Small quantum dots emit blue light, while larger ones emit red light. Because of their unique optical and electronic properties, quantum dots have many potential applications, including in displays, solar cells, medical imaging, and quantum computing.

You might have some nanotechnology products in your home.

Some articles of clothing are coated with zinc oxide nanoparticles which can protect the wearer from ultraviolet rays from the sun.

Silver nanoparticles embedded into bandages can help kill bacteria.

Clay nanocomposites are used in some packaging materials to block the flow of gases such as oxygen and carbon dioxide.

Transistors in many new computer chips are now at a scale where individual transistors are now measured in nanometers, and special techniques have to be used to create them as they are smaller than the wavelengths of light used to create the chips.

Nanotechnology is still in its infancy. Many ideas which were originally floated by Feynman and Drexler still have yet to be achieved. While some crude nanoscale machines have been built, but nothing close to a true nanobot has been built.

However, there is a great deal of work being done on it. Billions of dollars have been invested in what is considered one of the great frontiers of science in the 21st century.

If I were a betting many, I’d guess that many of the scientific advances we’ll see over the next several decades will be in the realm of nanotechnology.

The Executive Producer of Everything Everywhere Daily is Charles Daniel.

The associate producers are Thor Thomsen and Peter Bennett.

Today’s review comes from listener Sargent Salt over on Apple Podcasts in the United States. They write:

Thanks Gary

I once met Thor Thompson. He was suntanning on float ice above the wreck of Shackleton’s Endurance. But he doesn’t like publicity, so he politely got into his private zeppelin and sailed away.

Thanks, Sargent Salt! While I appreciate your comment, I’m going to have to call you out on this. I know for a fact that what you described isn’t true.

That is because I know Thor Thompson doesn’t need a zeppelin to be able to fly.

Remember, if you leave a review or send me a boostagram, you too can have it read on the show.