Magnetic levitation (maglev) can create frictionless, efficient, far-out-sounding technologies. Here are some of the craziest uses that engineers and designers have dreamed up.
1. Floating Cities
Our planet can be a crowded, polluted, crazy place. But a new design concept proposes that we rise above it all, literally, by moving to a magnetically levitated island in the sky, complete with green forests, mountains, and urban centers. The concept, called Heaven and Earth, was created by Chinese architect Wei Zhao and won an honorable mention in eVolo’s 2012 Skyscraper Competition. Zhao has proposed that the massive donut-shaped platform could hold magnets on its underside that would repulse the earth’s magnetic field to hold the island aloft. The floating platform would rotate, generating energy as it spins and theoretically fueling a completely sustainable society. Unfortunately, like most utopias, this idea is likely to remain a pie in the sky.
2. Super-High-Speed Rail
Regular high-speed trains can travel at up to 180 miles per hour, but they generate enormous amounts of friction and heat as they screech down the rails, leading to mechanical wear and energy loss. By contrast, maglev trains reach speeds faster than 300 miles per hour while hovering a few inches above the rail. By eliminating friction, maglev trains use less energy and can significantly reduce costs. For example, while every high-speed rail passenger pays one dollar for each mile traveled, maglev passengers could pay as little as 5 cents per mile, says James Powell, director of the company Maglev 2000 and a co-inventor of superconducting maglev trains.
A handful of maglev trains already exist in Asia and Europe, and several new projects may be in the works. Japan’s MLX01 clocked in at 361 mph in 2003—the highest speed yetfor a Maglev train—but China is reportedly developing a train that will double that speed. And by operating within airless tubes, maglev trains could potentially reach speeds of several thousand miles per hour. Speeds like that could make commuting effortless … that is, if the acceleration and deceleration don’t squash you first.
3. Space Launch System
For years, NASA has been researching the possibility of using the high speeds of maglev transportation to fling spacecraft into low Earth orbit. “It would really open up space to human exploration and commercialization,” Powell says. “It’s something we can’t do now because it’s too expensive.”
Powell and his colleagues have proposed two generations of space launching technology. The first is a cargo-only launch track that could be built into a mountainside to reach a height of 20,000 feet. Magnets could allow a spacecraft traveling along the track to reach speeds around 18,000 miles per hour—enough to fly into space. Of course, such a track would cost an astronomical $20 billion to build. That’s quite an up-front cost, but some, like Powell, argue that it could actually save money in the long run. It currently costs $10,000 to launch every kilogram of payload into low Earth orbit. StarTram could do the same for less than $50 per kilogram, he says.
And that’s just the first generation. A similar launch track for passengers might cost $60 billion and would need to be 1000 miles long, 12 miles high, and use magnetic levitation both to support the track and propel the train forward at speeds of 5.6 miles per second. Where companies like Virgin Galactic promise to take passengers into space for $200,000 per person, StarTram may charge as little as $50,000 per person.
4. Flying Cars
It’s not exactly what The Jetsons led us to expect, but SkyTran pods promise to bring maglev transportation to the skies. Each private pod, suspended from an elevated guideway, could carry three passengers and would use maglev technology to reach speeds of up to 150 mph. Theoretically, SkyTran could bring passengers anywhere they wanted to go along the route of the guideway, without making unnecessary stops for other passengers. The system could work using technology that is already available, and claims to be able to eliminate congestion while reducing carbon-dioxide emissions and dependence on foreign oil.
NASA has shown an interest in this technology, and in 2009 it partnered with Unimodal (the creators of SkyTran) to evaluate advanced transportation software.
5. 3D Cell Cultures
Cells grown in flat petri dishes are not always the most accurate models for three-dimensional human bodies. That’s what drove a group of medical researchers at the University of Texas and Rice University to levitate their cell cultures and allow them to develop in three-dimensional space.
The experiment was surprisingly easy. The researchers simply injected cancerous cells with magnetic iron oxide and gold nanoparticles, then added these cells to a regular petri dish. Then they put a coin-sized magnet on top of the petri dish and let the cells grow.
It turned out that the magnet could lift the cells off the bottom of the petri dish, and that the cells grew as they were suspended in the liquid. Compared to cells grown in regular petri dishes, the maglev cancer cells have a more similar structure and produce similar proteins to tumors in living animals. These tumor models could help researchers to develop better cancer treatments. The 3D development allowed by magnetic levitation may also be used to grow more realistic organs in the lab one day, the researchers say.
6. Efficient Wind Power
Standard wind turbines convert only 1 percent of wind energy into usable power, and part of that glaring inefficiency stems from the loss of energy due to friction as the turbine spins. Researchers at the Guangzhou Energy Research Institute have estimated that magnetically levitated turbines could boost wind energy generation by as much as 20 percent over traditional turbines.
The researchers proposed using a colossal turbine with vertical blades that are suspended above the base of the turbine using neodymium magnets. Because the moving parts wouldn’t touch, the turbines would be virtually frictionless and could capture energy from winds as slow as 1.5 meters (5 feet) per second. Maglev turbines could lower the price of wind energy to less than 5 cents per kilowatt-hour, which is on par with coal-generated electricity and only about half the typical cost of wind power.
The researchers say that a 1-gigawatt maglev turbine would cost $53 million to build and may require 100 acres of land, but it could supply electricity to 750,00 homes. In comparison, it would cost hundreds of millions of dollars to build a wind farm of similar capacity using traditional turbines, and it would require 64,000 acres of land to house the 1000 turbines.
7. Studying Weightlessness
Being weightless can have serious health consequences for astronauts. For every month that an astronaut spends in zero gravity, he loses one to two percent of his bone density (compared to the same amount per year for people on Earth). Muscles deteriorate, fluids redistribute throughout the body, and the immune system becomes weakened. Using magnetic levitation to simulate weightlessness here on Earth, scientists can better understand these changes and their consequences.
For many years, NASA scientists have used superconducting magnets to levitate insects, frogs, and mice. Cells are largely made of water, which is weakly diamagnetic. So in the presence of a strong magnet, water’s electrons rearrange to oppose the magnet. When researchers expose living organisms to superconducting magnets, this molecular effect causes the organisms to levitate.
Just a few months ago, floating fruit flies helped scientists to discover that weightlessness can change expression in over 200 fly genes. The genes most affected were responsible for metabolism, immune functioning, and cell signaling. It’s possible that humans show similar expression changes during weightlessness. By understanding how the body reacts to weightlessness, this research could eventually make prolonged spaceflight—such as a journey to Mars—safer for humans.
8. Magnetic Bearings
Magnetic levitation isn’t just for far-out technologies; it’s already being used in down-to-earth applications. Industrial equipment such as pumps, generators, motors, and compressors use levitation to support moving machinery without physical contact. The same bearings used to support maglev trains are used in electric power generation, petroleum refining, machine-tool operation, and natural gas pipelines.
These bearings also eliminate the need for lubrication, which is important in machines where lubricants can be a source of contamination, or in evacuated tubes where lubrication would fail. Magnetic bearings tend to be complex and custom-tailored to the machine, which can drive prices up by as much as $45,000 per bearing, but these low-friction parts could play increasingly important roles in industrial applications if their price comes down.