The microwatt-level battery is said to generate power from microbial respiration, delivering enough energy to run a paper-based biosensor with a drop of liquid containing bacteria.
“Dirty water has a lot of organic matter,” said Seokheun “Sean” Choi, whose work is published in Nano Energy. “Any type of organic material can be the source of bacteria for the bacterial metabolism.”
The method could be useful to anyone working in remote areas with limited resources. Because paper is inexpensive and readily available, experts working on disease control and prevention have already seized upon it as a key material in creating diagnostic tools for the developing world.
“Paper is cheap and it’s biodegradable,” Choi said in a statement. “And we don’t need external pumps or syringes because paper can suck up a solution using capillary force.”
While paper-based biosensors have shown promise in this area, the existing technology must be paired with hand-held devices for analysis.
Choi said he envisions a self-powered system in which a paper-based battery would create enough energy to run the biosensor. Creating such a system is the goal of a new three-year grant of nearly $300,000 he received from the US National Science Foundation.
Choi’s 5-cent battery, which folds into a square the size of a matchbook, uses an inexpensive air-breathing cathode. According to the paper, the cathode was created with activated carbon on the sprayed Nickel electrode.
The abstract further states: “By applying origami techniques, compact and stackable 3D battery structures were created from 2D sheets through high degrees of folding along pre-defined creases.
“The bacterial culture was added into two common inlets of the folded battery stack, through which it was transported into each battery.
“For operation, the battery stack was unfolded to expose all air-cathodes to the air, thereby maximising their cathodic reactions.”
For a direct link to the journal article: http://www.sciencedirect.com/science/article/pii/S2211285515002359