Fraunhofer Research scientists claim flexible, paper-thin batteries are on-track for a 2010 product launch. These ultra-thin batteries use organic semiconductors that can be mass-produced using printers, they will target applications such as smart credit cards with battery-powered displays to show balances and other account information. The German researchers say the organic materials produce 1.5V per cell, while using no hazardous chemicals like the heavy metals in conventional batteries.
The batteries are printed using a silk screen printing process in which a rubber lip presses the organic semiconductor materials through a screen onto a flexible substrate. The lithographic-like technique uses templates to pattern layer upon layer--each about the width of a human hair--of battery components until enough bulk has been achieved for a particular application. Printable batteries for smart cards would weight less than 1 gram and measure less that 1-mm thick.