Virus-Powered Battery Could Charge Your Cellphone by Walking
A Berkeley National Laboratory scientist demonstrates a virus-powered LCD display. The scientist pushes a square virus sandwich to create the electricity to show the "1."
CREDIT: Berkeley Lab
Engineers at the Lawrence Berkeley National Laboratory in California have created a unique system that uses a harmless virus to convert finger taps or other everyday motions, even walking, into electricity.
From the sway of train cars to the motion of humans walking, the world is full of little vibrations, so research groups have long looked for ways of turning that mechanical energy into electricity people can use. The Berkeley Lab generator is the first to use a biological material to turn mechanical stresses into electrical energy, according to the lab.
"More research is needed, but our work is a promising first step toward the development of personal power generators," Seung-Wuk Lee, a Berkeley Lab bioengineer who led the research, said in a statement. "Personal power generators" means devices, perhaps woven into clothes, which generate electricity from people's everyday movements. Virus-powered generators could also be used in nano-size electronics in the future, Lee said.
Materials that build up electric charges in response to finger taps, bending and other mechanical stresses are usually toxic, so the Berkeley Lab engineers were looking for something safer to work with. They decided to try a virus commonly studied in labs, the M13 bacteriophage. The bacteriophage targets bacteria and isn't harmful to people. It also naturally builds up a charge when stressed, the engineering team discovered.
They then turned to engineering the virus to ramp up its voltage. They used genetic modifications to enhance the charge difference in the proteins around the outside of the virus. They grew the virus in a way that it created neat, one-virus-thick sheets, then tested the sheets and discovered that 20-sheet layers created the strongest electrical effect. It takes just hours to grow millions of copies of the virus, so any device in the future that used it would always have a ready supply.
The researchers then sandwiched squares of the virus sheets between gold-plated electrodes and wired up the virus sandwich to an LCD display. When someone taps the sandwich, which is about 1 centimeter square, it generates about one-third as much electricity as an AAA battery. That's just enough to power the display to show the numeral "1."
Now that they've shown it's possible to get a virus to turn taps into electricity, the researchers will work on getting more power out of the bacteriophage, Lee said.
The lab scientists reported on their discovery in yesterday's (May 13) issue of the journal Nature Nanotechnology.
In the future, improved versions of this technology could gather power from doors as they open and close throughout the day. A super-thin virus sandwich could be built into the soles of shoes, so people might be able to charge their cellphones as they walk.