Micro power
August 3, 2009
A group of German scientists want to trim down heavy, bulky batteries to wafers thinner than a millimeter and lighter than a gram. The research team, led by Reinhard Baumann of the Fraunhofer Research Institution for Electronic Nano Systems (ENAS), also wants the new batteries to be produced by a cost-effective printing process.
"Our goal is to be able to mass produce the batteries at a price in the single digit cent range each," Andreas Willert, group manager at ENAS, said in a statement.
By placing several batteries in a row, voltages of 3 V, 4.5 V and 6 V can also be achieved. The battery contains no mercury and is in this respect environmentally friendly. Its voltage is 1.5 V. A standard AAA battery weighs about 11.5 grams and also runs at 1.5 volts.
The batteries are printed using a silk-screen printing method similar to that used for t-shirts and signs.
The printing process presses together layers of a zinc anode and a manganese cathode, as well as other materials. The zinc and manganese gradually react and produce electricity. The process makes it possible to apply comparatively large quantities of printing paste, and the individual layers are slightly thicker than a hair.
During the chemical process, the elements gradually dissipate, giving the battery a limited lifespan.
Currently, the battery is most commonly used in musical greeting cards, but researchers have said it could turn up in wide variety of places in the near future, including smart cards that would store security codes for a limited amount of time. Researchers said they hoped to finish other products using the batteries by the end of 2009.
Printed batteries are also used to provide power in smart packaging and toys. They run active RFID tracking chips and are used in medical sensors and cosmetic patches.
The industry for thin-film and printed batteries will reach $5.6 billion (4 billion euros) by 2015, according to an April report from analyst group NanoMarkets.
In addition to research groups like Fraunhofer and small and medium-sized companies pursuing the technology, large firms including Air Products, Dow Chemical, Intel, and NEC have also invested in printable batteries, the report said.
Author: Sean Sinico
Editor: Kate Bowen