Triboelectric Nanogenerator for Self-Powered Devices & Large-Scale Energy Needs
Georgia Tech professor Zhong Lin Wang is using what's known as the triboelectric effect to create surprising amounts of electric power by rubbing or touching two different materials together. "The fact that an electric charge can be produced through triboelectrification is well known," says Wang. "What we have introduced is a gap separation technique that produces a voltage drop, which leads to a current flow in the external load, allowing the charge to be used. This generator can convert random mechanical energy from our environment into electric energy." Since 2011, Wang and his research team have increased the power output density of their triboelectric generator by a factor of 100,000 – reporting that a square meter of single-layer material can now produce as much as 300 watts. They have found that the volume power density reaches more than 400 kilowatts per cubic meter at an efficiency of over 50 percent. The team has expanded the range of energy-gathering techniques from 'power shirts' containing pockets of the generating material to foot pedals and floats bobbing on ocean waves.
Transcript
00:00:00 [MUSIC PLAYING] We are in the School of Material Science and Engineering at Georgia Tech. We have invented a new energy technology I believe that can change the world we live in in the near future. We look for new energy, but energy is around us everywhere all the time. But most time, we waste it. Until recently, we found this can be a very important effect
00:00:26 for energy. Now, how does it work? So what you see here is A material and a B material. When they become physically contact, there's a charge transfer. If they are separated by a gap, there's a voltage generated. The second mode is sliding. If you have two materials, they slide at one against the other one, you can also have a charge here.
00:00:49 One mode is physical to contact, and the other one is sliding. This is the two basic modes we use for electricity generation. This is called triboelectrification electrification, or scientific, called contact electrification. And this occurs for almost any materials we know today. Why do we use nanomaterial here? But using nano structure on the surfaces, we get a large increase in the surface area and [INAUDIBLE] has the charge a transfer without using patent. With using the patent, the power density
00:01:23 is different by 1,000 times. When we first invented, this was fall of 2011, the output was just 3 volts. Today, our best can be 10,000 volts. Mechanical energy is everywhere, independent of weather, independent of day or night, independent of season. So anything you can think of-- smaller scale, from finger tapping, from your touch pad, from the walking, to car motion, even train motions, we can do that. We harvest energy we have been wasting for years.
00:02:02 We never use them. So I anticipate this can not only contribute the power source for portable electronics, but also can contribute power source for large scope energy need. It can contribute significantly to the worldwide energy need in the near future. And we even think for big ocean wave, theoretically they say 31 terawatt energy can be harvested. That's twice of today's world energy consumption.
00:02:30 It will not take too long-- five years.