Wearable power, one of the hottest researched topics in the wearable electronic field got another boost from researchers at the Fraunhofer Research Institution for Electronic Nano Systems EANS together with colleagues from TU Chemnitz and Menippos GmbH.
The research team led by Prof. Dr. Reinhard Baumann developed batteries that can be printed using a silk-screen printing method similar to that used for t-shirts or signs.
The paper battery is build up of different layers: a zinc anode and a manganese cathode, among others. Zinc and manganese react with one another and produce electricity.
The printed battery weighs less than one gram, is less than one millimeter thick which makes it flexible enough to be build into wearable electronic systems for seamless integration without producing a bulky area on garments.
Additional bonus: the battery contains no mercury and is in this respect environmentally friendly. Its voltage is 1.5 V, but by placing several batteries in a row, voltages of 3 V, 4.5 V and 6 V can also be achieved. It would be great if the paper batteries could be made rechargeable so they could be connected to flexible solar panels in clothing providing the greenest energy imaginable for our power hungry gadgets.
Fantastic view also on the expected cost of these batteries: according to Dr. Andreas Willert, group manager at ENAS, the goal is to ‘… be able to mass produce the batteries at a price of single digit cent range each‘.
However there are some limitation that will limit the use of a paper battery to certain, low power applications like sensors: the anode and the cathode layer dissipate gradually during the chemical process, having a shorter life span compared to conventional batteries.
Which is not as bad as it might sound. Being able to use cheap battery power sources for wearable application, carefully selected for the low power capability, is still a good reason for me to anticipate the availability of such batteries.
A shorter lifespan should not be a blocking point as clothing items go out of fashion faster than this battery will lose it’s power and using environmentally friendly materials for the paper battery makes the short lifespan a tolerable fact as well – from the view of an wearable electronic technologist.