Look mom, no wires – Or how MIT scientists use induction energy to (wirelessly) light a 60 watt bulb

Earlier this week, MIT researchers announced they had made a 60-watt light bulb glow by sending energy to it wirelessly. They call their self-proclaimed breakthrough “WiTricity“.

The concept of sending power wirelessly isn’t new. In fact, it was dicovered aprox. 100 years ago by Nikola Tesla. Its wide-scale use has always been considered “inefficient” because electromagnetic energy generated by the charging device radiates in all directions.

In this photo released by Massachusetts Institute of Technology, members of the team that performed an experiment demonstrating wireless power transmission from the coil on the left to the coil on the right, where it powers a 60W light-bulb, are seen. Members of the team that performed the experiment are, Peter Fisher, Robert Moffatt, Marin Soljacic, Andre Kurs, John Joannopoulos and Aristeidis Karalis.

The MIT wizards have found a way to bundle the energy waves in a resonating way, thus allowing them to transport the energy much more efficiently.

The MIT team demonstrated the principle by lighting a 60 Watt light bulb, approximately 2 meters away from the power generator.

“It was quite exciting,” Soljacic said. The process is “very reproducible,” he added. “We can just go to the lab and do it whenever we want.”

The development raises the prospect that we might eliminate some of the clutter of cables in our ever-more electronic world. Is that necessarily a good thing? Soljacic acknowledged “that it’s far from obvious how crucial people will find this.”

But at least one benefit could be that if devices can get their power through the air, they might not need batteries and their attendant toxic chemicals.

Before that can happen, the technology has a ways to go.

The MIT system is about 40 percent to 45 percent efficient – meaning that most of the energy from the charging device doesn’t make it to the light bulb. Soljacic believes it needs to become twice as efficient to be on par with the old-fashioned way portable gadgets get their batteries charged.

Also, the copper coils that relay the power are almost 2 feet wide for now – too big to be feasible for, say, laptops. And the 7-foot range of this wireless handoff could be increased – presumably so that one charging device could automatically power all the gadgets in a room.

Soljacic believes all those improvements are within reach. The next step is to fire up more than just light bulbs, perhaps a Roomba robotic vacuum or a laptop.

The MIT team stresses that the “magnetic coupling” process involved in WiTricity is safe on humans and other living things. And in the initial experiments on the light bulb, nothing bad happened to the cell phones, electronic equipment and credit cards in the room – though more research on that is needed.

The harmlessness apparently extends both ways: The researchers noted that putting people and other things between the coils – even when they block the line of sight – generally has no effect on the power transfer.

Credits: MIT and citizen-times.com