Roll-to-Roll Printed Flexible Electronics and Applications
Flexible electronics have many shapes and forms, resulting in very diverse application domains. Most of the flexible electronics applications are targeting consumer end of markets, which requires the products to be both flexible and low cost. The only viable route to low-cost manufacturing of flexible electronics is by printing, and preferably by roll-to-roll (R2R) printing. Over the years, electronic ink technology has been well developed and many ink materials, especially conductive inks, have established their own market. Flexible electronic systems, particularly the flexible circuit systems, can be printed by inkjet, screen or gravure printers. The added benefit of printing flexible circuits instead of the conventional printed circuit board (PCB) manufacturing is its green process with much less or no pollution issues. The Printable Electronics Research Center (PERC) at Suzhou Institute of Nanotech, Chinese Academy of Sciences, has been developing electronic ink materials and printing processes for 10 years. A spin-off company has been set up to explore printed electronics technologies for commercial applications. R2R screen printing of flexible electronic circuits has been realized. An in-line photonic sintering technology has been developed to sinter both nanosilver ink and nano copper ink. Flexible electronics applications in RFID tags, smart carpet, and in-car electronics have been explored. The team also invented and patented a novel hybrid printing process to fabricate embedded metal mesh as flexible transparent conductive films. The technology has been transferred to industry and implemented in R2R mass manufacturing in the volume 1.5million piece per month. Touch panels integrating the metal mesh films have been commercialized.