科学美国人60秒 SSS 行走时可收集能量的背包（在线收听）

This is Scientific American's 60-second Science, I'm Christopher Intagliata.

这里是科学美国人——60秒科学系列，我是克里斯托弗·因塔格里塔。

When you walk with a backpack, you know how the stuff inside sways from side to side? Nowscientists have figured out how to tap into that motion to generate electricity.

当你背着背包走路时，你知道包里的东西是如何左右摇晃的吗？现在科学家已经知道如何利用这种运动来发电。

Here's how it works. Picture a pendulum mounted to a backpack frame and stabilized withsprings on either side. The pack's weight is attached to the pendulum, so the pendulumswings side to side as you walk. Gears then use that swinging motion to drive a generator, andthe generator spits out electrical current to charge a battery.

下面来解释其工作原理。想象一个钟摆被装在背包框架上，然后用框架两边的弹簧固定。背包的重量与钟摆相连，因此你走路时钟摆会左右摆动。之后，齿轮会用这种摆动来驱动发电机，而发动机会吐出电流为电池充电。

Volunteers carried the pack while walking on a treadmill and wore masks to measure the flowof oxygen and carbon dioxide. Walking with the slightly swaying 20-pound load, the device didnot significantly affect the volunteers' metabolic rate compared to when they carried thesame weight fixed in place. In fact, the energy-harvesting pack reduced the forces ofacceleration they'd feel in a regular pack, which might mean greater comfort for a long hike. And the device did produce a steady trickle of electricity—the operative word being trickle.

志愿者背着背包在跑步机上走路，他们同时戴着口罩测量氧气和二氧化碳的流量。与相同重量的固定负重相比，在轻微晃动的20磅负重下行走时，该设备未对志愿者的新陈代谢率产生显著影响。事实上，收集能量的背包减少了他们在普通背包中感受到的加速力，这可能意味着长距离徒步时背这种背包会更加舒适。这个装置确实产生了稳定的电细流——关键字是细流。

Because if you up the load to 45 pounds, the passive motion of the pack could fully charge aSamsung Galaxy S10 smartphone only after 12 hours on the trail. The details are in the journalRoyal Society Open Science.

因为如果把负重加到45磅，那在走路时，背包的被动运动只需12个小时就能给三星Galaxy S10智能手机充满电。研究详情发表在《英国皇家学会·开放科学》期刊上。

But here's the rucksack rub: the energy-harvesting device currently weighs five pounds. Theresearchers say that's about four pounds too many to be a smart alternative to batteries. Sothey hope that more research lets them lighten the load, to ensure the pack charges you upwithout weighing you down.

但现在有个背包困难：目前收集能量的设备重达5磅。研究人员表示，这个多出约4磅的设备不能作为电池的智能替代品。因此，他们希望，更多的研究能让他们减轻这一负担，确保背包在不让你感到沉重负担的情况下为你充电。

Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.

谢谢大家收听科学美国人——60秒科学。我是克里斯托弗·因塔利亚塔。