Here Comes Second Generation Printed Electronics
By Dr Peter Harrop
Second generation printed electronics has arrived and its impact on society will be immense. A major new industry is born. Transparent solar cells will be on watches by year end and vast areas of printed flexible photovoltaics will be available within the next few years. Heliovolt promises a high efficiency silicon-free photovoltaic film in 2007. Polymer alternatives will have lower efficiency but often be lower in cost. Announcements have yet to be made but IDTechEx has identified several companies that will be commercialising polymer solar film in 2007.
Light emitting moving colour displays, vehicle and room lighting on flexible substrates, the electronic book and many forms of disposable electronics are near to mass rollout. An example of a Sony e-book developed with e-ink electrophoretics is shown below. Some new versions are flexible and use printed polymer Thin Film Transistor Circuits TFTCs from Plastic Logic as back plane drivers. Working samples of these have been widely available in 2006.
This year saw smart drug packs with printed sensors and sometimes printed batteries. These have unique electronic identification and they record which pill was removed when, because 50% of patients take their medication incorrectly. Initially they are being used to improve drug trials such as the National Institute of Health trial of Azithromycin and a Novartis trial this year. We already have flexible, electroluminescent colour displays from billboards to animated watch backgrounds.
Potential markets for low cost printed and thin film photovoltaics vary from feeding national power grids to use on smart packaging and toys. We need photovoltaics that is one tenth of the manufacturing cost and installation cost of today’s silicon solutions and with none of their supply shortages. Within reason, it will not matter if the replacement has a larger footprint, particularly if it is flexible and/ or transparent. If its efficiency is 5-10% vs double or treble that for silicon, it will not matter in most applications because the other benefits will prevail. For example it can go over a window or conform to the shape of a vehicle. However, it is a challenge to achieve the 10,000 hours life necessary for an entry level printed product and 50,000 hours for mainstream use. The same can be said of OLED displays, signage and lighting on flexible film but progress is being made and products are starting to sell.