Advancing Basic Science for Humanity
01/02/2020 - Year-End Innovation: Nanoscience Highlights
By Alan S. Brown
In a surprising new study, University of California, Berkeley, researchers show that heat energy can travel through a complete vacuum thanks to invisible quantum fluctuations. To conduct the challenging experiment, the team engineered extremely thin silicon nitride membranes, which they fabricated in a dust-free clean room, and then used optic and electronic components to precisely control and monitor the temperature of the membranes when they were locked inside a vacuum chamber. (UC Berkeley photo by Violet Carter)
This past year has been a banner year for nanoscience, and December—a month in which things typically wind down—is no exception. What really jumps out is how researchers are taking advantage of decades of basic research to innovate in remarkable ways. This month, for example, we gained new insights into the mutations that cause muscular dystrophy. And on the physics side, we look at the basic building blocks for 6G phones and how heat can pass through a vacuum in the quantum mechanical world. And to finish off, we have microscale robots the size of a cell that contain moving parts, a solar power energy source, and computer circuits.
- A new way to attack muscular dystrophy?
There are more than 500 different protein mutations that cause disease in the body. Why do most of them only cause disease in muscles and not the brain, liver, or other tissues? That’s the question that perplexed Jan Lammerding, a member of the Kavli Institute at Cornell University. His research focused on mutated lamins, proteins that surround the cell nucleus, which stores DNA. In most body tissue, the lamins reduce the stability of the nucleus, which is tied to the cell wall, but this is not a problem. In muscles, however, the mechanical forces generated by the muscles undermine the stability of the nucleus and cause the envelope protecting it to rupture, damaging the DNA inside. This is a new way of looking at some forms of muscular dystrophy, and it suggests several new avenues to search for cures.
- Getting ready for 6G phones.
Everyone is talking about 5G wireless networks, and for good reason. They will not only bring faster smartphones, but also link together our homes, vehicles, medical information, and factories. This is going to take a lot of bandwidth, and that means higher frequencies. In fact, the second wave of 5G phones (as well as next-generation 6G networks) will operate at frequencies above 30 gigahertz, five times higher than today. That will require new materials, and Darrell Schlom and David Muller of the Kavli Institute at Cornell for Nanoscale Science are leading the charge to create them. This is more difficult than it sounds. Several years ago, they developed a material that operates at those high frequencies. Unfortunately, it was lossy (inefficient) and heated up, which is a problem in a thin smartphone. They solved the problem by creating a less random material, but to do that, they had to find a way to synthesize a material that just did not want to go where they applied it.
This layered structure of strontium (not colored), barium (red) and titanium (teal) is a tunable dielectric that can improve the performance of high-frequency electronics.
- Vacuum cannot stop quantum heat.
Anyone who ever put coffee in a glass thermos knows that it will keep it hot for hours. This is because the inner container is separated from the outside by a vacuum. Heat can’t get through a vacuum because it radiates by causing molecules to vibrate. Since there are no molecules in a vacuum, heat cannot cross it. That is true at the macro level, but at the quantum level, this is not exactly the case. In quantum mechanics, no space is ever empty. It is filled with field fluctuations. When two objects are close enough—nanometers apart—one object can transmit its vibrations to the other. Now researchers at the Kavli Energy Nanoscience Institute at Berkeley have demonstrated this. It may sound obscure, but many of the nanoscale features on computer chips are close enough for these interactions to make a difference. Understanding this interaction could help build cooler running chips in the future.
- Microrobot talk honors Millie Dresselhaus.
MIT’s Millie Dresselhaus was known as the Queen of Carbon, and was awarded the 2012 Kavli Prize in Nanoscience for her work decoding the structure of buckyballs and nanotubes. MIT created a memorial lecture in her name, and named Paul McEuen, co-director of the Kavli Institute at Cornell for Nanoscale Science, to give the first talk. His topic: microscale robots made from thin sheets of semiconductors. McEuen’s robots are only 100 microns in size, about the size of a cell and the border between the visible and the invisible (or microscopic) world, he explained. McEuen builds them by sculpting nanoscale circuits and solar cells into the semiconductor, then using origami bends and folds to turn it into a 3D object. McEuen can make tens of thousands of them on a single silicon wafer, and believes they will become the components of a microscale mechanical revolution that may one day rival what we have achieved with computers.