无线“电”让电线和电池成历史

不再需要电池和充电器，也不用再看着纠结在一起的电源线发愁。本周在拉斯维加斯的国际消费电子产品展会上展出的一项叫做“无线电源”的电力传输方式将可以通过空气向笔记本电脑、iPod以及其他便携式电子设备输送电力。只要身处开通了无线电源的房间或者把电子设备放在具备传输功能的桌子上，设备就会自动进入充电状态，手机突然没电的烦恼也将不复存在。“充电”之类的字眼也将从字典中消失。

　　No more batteries, no more chargers and no more wire spaghetti. This is the future promised by "wireless power", a means of broadcasting electricity through the air to laptops, iPods and other gadgets without the need for cables and sockets.

　　Untethered lighting, audio speakers and digital picture frames are expected to be among the first commercial products demonstrated in Las Vegas this week at the International Consumer Electronics Show, the world's biggest gadgets tradeshow.

　　Experts believe this is just the beginning and that eventually wireless electricity - dubbed "WiTricity" by some - could do for battery life what WiFi did for the Internet. In a world without wires, laptop users in cafes and airport terminals would be inside an "electricity hotspot" and no longer have to delve past legs, bags and furniture in search of an awkwardly located socket.

　　"You'd be able to buy a desk that charged any gadget placed on it, or power any PC you put on top," said James Holland, editor of gadgets website Electricpig.co.uk.

　　"If each room had wireless power, you'd know that once you walked through the front door your mobile would start charging up - even while still in your bag or pocket. You'd never need to hunt for the right charger again."

　　Among the companies showcasing the ambitious technology at CES is PowerBeam. Its system turns electricity into an invisible laser, then literally beams it, as heat, across the room to a solar cell that converts it back into electricity.

　　David Graham, the co-founder of PowerBeam, said: "We're going to delete the word 'recharge' from the English dictionary. If your cell phone is recharging on your desk all day, you won't be thinking about it."

　　The Silicon Valley company can currently use a laser to generate about 1.5 watts of power to a solar cell 10 meters away. This would be enough to power an electronic speaker or small LED lights, but not enough to operate a laptop, which requires an estimated 30 to 50 watts. However, Graham said that the technology could comfortably be scaled up.

　　PowerBeam insists its laser does not pose a risk to users' health because it is simply moving heat from one place to another. Graham said that, if someone walked through the beam, it would shut down within a thousandth of a second, then restart once the path is clear. The technology also promises energy efficiency because it would only power products when needed.