Scientists create foldable paper battery based on bacteria

Researchers at the University of Birmingham have created a paper foldable battery that extracts energy from bacteria. The battery is intended to power sensors and other devices that require little electricity.

The system is primarily intended to provide energy to disposable sensors in a cheap way. By using paper, there is no need to make a separate reservoir for the bacteria: the paper functions as a reservoir. By then folding the different batteries so that they are in series, they can supply more energy.

The researchers were able to provide sufficient energy with just a drop of water containing bacteria. The bacteria provide energy through their metabolism: when bacteria process certain substances, electrons are released that can be transferred to the carbon anode. Normal ‘dirty’ water already contains enough bacteria to make the paper device produce energy, the researchers write in their paper. After about eighteen minutes, the tested setup delivered a voltage of 0.93V.

The whole consists of an anode, paper, a pem with the cathode on top. The cathode does not contain expensive metals, but is formed by nickel that is sprayed onto the paper. The anode consists of carbonaceous paint.

It is also not necessary to include small pumps in the entirety to get the water to the right place: the paper absorbs the water by itself. All in all, according to the builders, the whole costs less than five cents each.