Understanding the Race for a Room Temperature Superconductor

Thirty years ago, before I went to college, I had my first introduction to a circuit board at the Boeing Company. My job title at that time was decalmaker in a shop responsible for making many of the decals used on the airplane. It also had a small subset of work performed by two metal plating experts with backgrounds in chemistry and I was taught to help them. One job involved creating a circuit board used by the vacuum tube system that shipped blueprints around the factory. The board basically just controlled on, off and the location where the device travelled.

The circuit board was a piece of hard insulation sandwiched between two pieces of. We used a product from Kodak, called photo-resist, which hardened on metal and formed a layer that acid did not eat through quickly. We'd spray on the photo-resist, expose it to light, then dip the part in acid until any unwanted metals or metal dye called anodize were removed. We'd also connect the board to an electrical current and place it in a bath of the metal until it formed on top of the copper either gold or lead; the result was the circuit board had a conducting path that would join electronic parts attached to the breadboard with weld into a complete circuit. A hole was punched at exact points in the breadboard for the attached electronics using a drill with magnifying capability.

To illustrate just how far electronics have changed in the past thirty years to add components, reduce distances between components and reduce energy loss along the circuit especially in the area of research in superconductors which have no resistance, here's a rundown of recent (past couple of years) semiconductor research and technology:

Breadboard vs. Etched Nanoscale Superconductor Circuit

In June 2010, scientists from Bar-Ilan University, Israel and Brookhaven National Laboratory announced they fabricated a thin film approximately 150 x 500 nanometers (that's one meter divided by a billion) with loops that had a 25 nanometer diameter, or 6 loops across and 20 over. These loops carried current without resistance (the goal behind finding a superconductor) when cooled below 30 Kelvin. That's a huge reduction in circuit size in thirty years. Using molecular beam epitaxy, the scientists used layers of copper-oxide and lanthamum and strontium to reduce the already small sizes even further. They also reported oscillations in resistance when a magnetic force was applied perpendicular to the etched film.[1]

Metal Plating vs. Epitaxial Layering

In several papers by NASA scientists, silicon carbide semiconductor based electronics have been found to perform better i.e. operate better using high power or in high temperature conditions. Silicon wafers are produced by a number of methods where the minerals are melted until it turns to vapor then allowed to re-crystallize. With silicon carbides, the problem has been that the crystal structure has caused defects in the material that reduces performance, and several techniques were analyzed to find improvements.[2][3]

Another study by Stanford University scientists working with Brookhaven Laboratory showed that current flowed along crystal edges in ceramic materials known as pnictides.[4]

Switch vs. Gesture Recognition Using Accelerometers

In March 2009, researchers at Motorola reported they had developed a technique using low cost accelerometers, an electronic device, to program a set of personal gestures that matched generic gestures. Accelerometers measure acceleration in a given direction. The researchers used algorithms that calculated the change in acceleration in any direction to predict the appropriate gesture - up, down, right, left, circle right, circle left, etc. Their programs are used in cellular telephones and other handheld media to produce more sensitive and more accurate results at a smaller cost than using virtual reality gloves. The researchers believe it will be useful for user identification based on personal gestures and for any other hand movement interactions.[5]

Conclusion About Superconductors and Other Semiconducting Materials

These articles are just a taste of what is being researched. In general, materials science especially related to semiconductors and superconductors (which reduce energy costs but cost to cool them to the point where they superconduct) will continue to change the modern world as we become more effective at computing, with costs related to heating silicon, and other minerals, in the crystallization process where the heated vapor is cooled into thin strips and in operating equipment in much more refined fashion.

[1] Brookhaven Laboratory, "Scientists Create Nano-Patterned Superconducting Thin Films", physorg.com, June 14, 2010

[2] Philip G. Neudeck, "Silicon Carbide Technology", NASA Glenn Research Center, October 25, 2006

[3] Philip G. Neudeck, "Growth and characterization of 3C-SiX and 2H-AIN/GaN films and devices produced on step-free 4H-SiC mesa substrates", NASA Glenn Research Center ,January 21, 2007

[4] American Physical Society, "Stripes offer clues to superconductivity", physorg.com, May 17, 2010[5] Jiayang Liu, Zhen Wang, Lin Zhong, Jehan Wickramasuriya, Venu Vasudevan, "uWave: Accelerometer-based Personalized Gesture Recognition and Its Applications