Producing electrical power with cardboard, tape, and a pencil

January 26, 2016 by Cécilia Carron
Producing electrical power with cardboard, tape, and a pencil

A small device made from everyday materials can generate enough energy to power several diodes. This clever discovery by an EPFL postdoctoral student was presented yesterday at a global conference on micro- and nano- systems in Shanghai.

All you need to generate a little electricity is cardboard, Teflon tape and a pencil. A team from EPFL, working with researchers from the University of Tokyo, used these materials to make an 8-cm2 device that can generate more than 3 Volts of power: a simple, eco-friendly and inexpensive system that can produce the same current as two AA batteries – enough to operate a remote control.

It all starts with static electricity

The principle underlying this system is well known: static electricity. When two insulators like paper and come into contact, they gain or lose electrons. The system is made up of two small , where one side of each card is covered in pencil. The carbon serves as the electrode.

Teflon is then applied to the opposite side of one of the cards. When brought together, they make a sandwich: two layers of carbon on the outside, then two layers of paper, and one layer of Teflon in the middle. They are then taped together in such a way that cannot touch (see the video for more details), giving the system a configuration that makes it electrically neutral.

The video will load shortly

By pressing down with your finger on the system, the two insulators come into contact. This creates a charge differential: positive for the paper, negative for the Teflon. When you release your finger and the cards separate, the charge passes to the carbon layers, which act as electrodes. A capacitor placed on the circuit absorbs the weak current that is generated.

To boost the device's output, Xiao-Sheng Zhang, a postdoc at EPFL's Microsystems Laboratory and the University of Tokyo, used sandpaper. Pressing the sandpaper firmly against the cards gives them a rough surface. This increases the contact area, which in turn improves the system's output six times. If you press your finger on the cards at a rate of 1.5 times per second, for a short period of time the capacitor will release the same amount of voltage as that supplied by two AA batteries. This is enough to power micro- or nano- sensors, which need only a little electricity to run.

The first 'TENG' made with household materials

This type of system is quite promising since it can be constructed with everyday items. Research on the use of to generate energy, dubbed 'TENG' (triboelectric nanogenerator), began in 2012. "The one that we developed in the framework of this European project is the first one to use natural, everyday and environmentally friendly materials," said Jürgen Brugger, a professor at the Microsystems Laboratory. This could have applications in the medical field, for example. Ultra low-cost sensors made of paper for various diagnostic purposes, which would be especially practical for developing countries, are already being tested. This paper system could represent the next step, since it would remove the need for conventional batteries. Another advantage is that it does not generate waste, since it can simply be incinerated or left to decompose naturally.

The IEEE-MEMS conference, where this device was just presented, is the leading global congress in the area of nano- and micro- systems.

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19 comments

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Protoplasmix
5 / 5 (1) Jan 26, 2016
A team from EPFL, working with researchers from the University of Tokyo, used these materials to make an 8-cm² device that can generate more than 3 Volts of power: a simple, eco-friendly and inexpensive system that can produce the same current as two AA batteries – enough to operate a remote control.
Volts isn't power, it's a difference in electric potential. If you connect a conductor between that difference then electric current will flow in the conductor. And electric current is not power either – power (in Watts) is the product of the potential difference (in Volts) times the current (in Amperes).

Nevertheless, it's very cool to know how easily it can be done.
PPihkala
5 / 5 (1) Jan 26, 2016
I agree, they are mispresenting voltage, current and power in this article. It would also be good to know what is the efficiency of this mechanical energy (finger push) to electrical potential conversion. But I bet that 8 cm2 of solar cell would give more power than this static generator. And the current available from two AA's is even more, despite the fact that the voltage might be similar 3V.
promile
Jan 26, 2016
This comment has been removed by a moderator.
Cave_Man
5 / 5 (3) Jan 26, 2016
Since when is Teflon environmentally friendly?
retrosurf
5 / 5 (5) Jan 26, 2016
Don't worry, Cave_Man. You can also use pine pitch in place of the teflon.
This is a new spin on an old invention: the electrophorus.
It's an electrostatic induction machine.
JBlog
5 / 5 (2) Jan 26, 2016
For a Science journal, this article shows an appalling lack of technical literacy.

It totally confuses Volts, Amps, and Power, and makes the idiotic claims that it can "power several diodes", and "can produce the same current as two AA batteries"....

Then the video attempts to mislead by using a bare LCD panel with the segments physically strapped together to display "Hi".

There is no driver chip of course, because that would draw too much current.

The whole point of a LCD panel is that it can operate on vanishingly small amounts of power.

david_king
4 / 5 (2) Jan 27, 2016
Hey if you just wanted to generate light energy instead of pushing a few liquid crystals around you can sit in the dark repeatedly peeling paper bandaid wrappers and sticking them together again. Endless fun until all the stickum ends up on one side or the other.
jimbo92107
5 / 5 (2) Jan 31, 2016
I suppose you could work this tech into the soles of shoes, maybe generate enough power to light a one-diode xenon LED flashlight. Or forget it and use the one on your key chain.
promile
Jan 31, 2016
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Protoplasmix
not rated yet Jan 31, 2016
Actually the triboelectric generators can get surprisingly high power density and given the fact, they're very lightweight, and they don't require expensive metals (copper wires) and/or neodymium magnets, they could became the mechanoelectric generators of the future.
Remember this article? Graphene battery demonstrated to power an LED

Already in a nearby alternate timeline the family's home robot produces devices incorporating a similar power supply as it guides the extruder/laser assembly over the work area like a 3d printer-without-the-box. I imagine.
promile
Jan 31, 2016
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MR166
not rated yet Jan 31, 2016
"that can generate more than 3 Volts of power: a simple, eco-friendly and inexpensive system that can produce the same current as two AA batteries – enough to operate a remote control."

Are the authors of this article really that ignorant or are they trying to purposely mislead us?
This seems to be a disease of all "eco-friendly" reporters.

Protoplasmix
not rated yet Jan 31, 2016
I wouldn't hurry so much: the findings like this one are suspicions for mainstream physics and they never get replicated.
The physics in the paper ( http://arxiv.org/abs/1203.0161 ) looks "mainstream" to me. Are there any papers mentioning difficulty with reproducing the results?
MR166
not rated yet Jan 31, 2016
Just examine most of the green energy reporting. The projects never produce the amount of power that the developers and science reporters claim they will. Most of the reporting is pure propaganda produced to acquire funding. Look at the PR for the average solar project. 90% of the time only the peak power output is ever quoted when the power it will produce is mentioned.
promile
Jan 31, 2016
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Protoplasmix
5 / 5 (2) Jan 31, 2016
...the accidental findings unexpected with mainstream physics are never ATTEMPTED to replicate. The physicists today follow only the ways, which are already predicted by their theories.
What exactly is unexpected or unusual about converting electromagnetic radiation and/or kinetic energy (both are involved in this case) to a usable form of electric potential energy?
promile
Feb 01, 2016
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MR166
not rated yet Feb 01, 2016
Lets see...perhaps I misspoke about the ignorance of the average green energy reporter. I can drag my feet across a carpet in a dry room and produce the VOLTAGE OF 2 OR 3 THOUSAND AA cells without much trouble. No on second thought they are all ignorant.
Anakin
not rated yet Mar 06, 2016
Where can i buy that tape or similar?

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