A demonstration of the paper-powered bio battery. The cylindrical case (upper right) is used for decomposing paper such as cardboard.
A demonstration of the paper-powered bio battery. The cylindrical case (upper right) is used for decomposing paper such as cardboard.
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A sheet-like battery made by reducing the thickness of the glucose-powered bio battery (right). A birthday card containing the sheet-like battery (left) plays music when juice, etc is spilled on it.
A sheet-like battery made by reducing the thickness of the glucose-powered bio battery (right). A birthday card containing the sheet-like battery (left) plays music when juice, etc is spilled on it.
[Click to enlarge image]

Sony Corp exhibited a bio battery that generates electricity by using paper as fuel at Eco-Products 2011, a trade show focused on green technologies, which runs from Dec 15 to 17, 2011, in Tokyo.

Though Sony showed a bio battery that uses glucose, etc to generate electricity at Eco-Products in the past, this is the first time that the company has announced the paper-powered bio battery (See related article).

The paper-powered bio battery uses an enzyme to decompose paper into glucose and uses the glucose for power generation. For the decomposition, Sony uses an enzyme called cellulase, which decomposes cellulose. This time, the company employed cellulase produced by Denmark-based Novozymes.

When paper is soaked in a solution that contains the enzyme, it starts to decompose into glucose. When the solution, which also contains glucose at this point, is poured into the battery, power generation starts. Because cellulase functions as a catalyst, it can be collected for reuse.

The bio battery itself is not much different from the one announced before. However, Sony said, "We improved power generation capability. And the new bio battery operates even when there are impurities generated by decomposing paper other than glucose."

In theory, the battery can generate up to 18Wh of electricity (equivalent to the amount that can be generated by six AA batteries) with glucose obtained by decomposing a piece of A4-size paper, Sony said. However, the battery currently can generate a much lower amount of electricity. Sony did not disclose the details of the bio battery's performance. But, in 2010, the company said that its glucose-powered bio battery could output 10mW/cm2.

This time, Sony made a sheet-like battery by reducing the thickness of its previous bio battery powered by glucose (or cola, orange juice, etc), embedded it in a Christmas card and so forth and demonstrated power generation with it.