Nico Chaparro - The Future of the Future

With technology getting better and better every day, and electronics getting more powerful in smaller sizes, we have to hit a point where we cannot possibly get any better right? The latest MacBook Air is already so thin and light, yet it is more powerful than the room-sized computer that was the first computer to be invented. The MacBook Air obviously does not require as much power as however much power a room-sized computer requires. How are electronics improving so much, and when will we hit a brick wall? Superconductors are a significant part of that explanation.

Moore’s Law states (in simple terms) that every two years electronics will get twice as powerful. This is because companies manage to fit more transistors (an item in electronics that is on the nanometer scale) in a tiny space, but soon enough we will reach a point where we simply cannot shrink their size as we reach the atomic level. So, it seems that once we cannot keep improving electronics in this way, as we have for so many years, we will reach our limit. However, superconductors can help us make electronics more powerful in a slightly different fashion.

A superconductor is a material (metal or otherwise) that has practically zero electrical losses when carrying a current (power). This, of course, is very desirable, because less power losses leads to more efficient electronics that require less power. If electronics were made with superconducting wires, they would be extremely efficient compared to electronics today. Who doesn’t want a smartphone with double the battery life as their current smartphone in the same form factor? All of our current electronics and their wires lose power constantly, but a superconductor can carry a current for practically forever. They lose a very small percentage of power over the span of multiple years! This is a drastic improvement over modern wires.

 

Figure 1: An Older Computer by IBM

Jenkins, A. (Photographer). (2010, August 8). IBM JX. Retrieved from https://www.flickr.com/search/?text=first%20computer&license=2%2C3%2C4%2C5%2C6%2C9

Superconductors can be useful in much more than just wires, though. They can be used as magnets as well in other ways. A very interesting trait of superconducting magnets is that they can levitate below a magnet through attraction to the top magnet, rather than simply levitating over a magnet through repulsion away from the lower magnet (as current magnets do). MAGLEV (magnetic levitation) trains are very fast, highly efficient, and work through magnets levitating from repulsion. Imagine what crazy inventions we might get when engineers find a use for this superconducting levitation below a magnet. Some possible applications of superconductors include more efficient and powerful computers, better MAGLEV trains, and better boat engines (Lundy, Swartzendruber, Bennett, 1989). Naturally, you have to wonder why we are not using superconductors universally right now. That’s where it gets a bit tricky.

Common metals used as wires or in electronics, such as copper, can become superconductors at certain temperatures, because of some complex chemistry and physics. However, those temperatures are extremely cold, and they are far from room temperature. For example, mercury wire is a superconductor but at -452F. This critical temperature changes depending on the material. A rare-earth material called YBCO was discovered in 1987 to be a superconductor at -292F. This is a much better temperature than mercury wire but still a very cold critical temperature. One of the least cold critical temperatures of -231F was found in a non-rare earth compound in 1988, and this compound was more stable as well. These extremely low temperatures are achieved using liquid nitrogen, which is cold enough for these tests to be done. As a result, more testing needs to be done to find materials that are superconductors at more reasonable temperatures to be used in our day to day electronics. Temperature, though, is not the only obstacle in bringing superconductors into modern devices (Lundy, Swartzendruber, Bennett, 1989).

Ceramics are the superconductors with the warmest known critical temperatures (around -200F), but they are brittle. Even if they did have critical temperatures around 80F, they would need to be strong enough to use in our devices. One of the factors in the strength of a ceramic superconductor is its shape. The problem lies in finding shapes for the ceramics that will allow them to be useful in devices while also making them strong. This is not so easy when circuits are generally small, and the ceramics have to be small as well to fit in them. Temperature and material strength are two of the most significant issues with creating usable superconductors (Lundy, Swartzendruber, Bennett, 1989).

So, if and when we do manage to make room temperature superconductors a reality, what can we expect? Some uses are up to 40% lifetime savings in huge generators, which is a substantial economic saving, even better, more powerful MacBooks and iPhones with much longer battery lives. Other applications are smaller and quieter boat motors, even more efficient MAGLEV trains, superconducting magnets, and a large amount of medical applications (Lundy, Swartzendruber, Bennett, 1989). These are the types of things that make the future a reality, and they should come around sooner or later.

By: Nicolas Chaparro, University of Florida

References:

Lundy, D. R., Swartzendruber, L. J., & Bennett, L. H. (1989). A Brief Review of Recent Superconductivity Research at NIST. Journal of research of the National Institute of Standards and Technology, 94(3), 147–178. doi:10.6028/jres.094.018