The development of digital printing technologies for flexible electronics devices

Abstract

There is an increasing demand for flexible electronics and optoelectronic devices, which requires designing and developing electronic devices on flexible substrates. Realization of flexible electronics with comparable or equal performance to conventional silicon-based microelectronics could enable a significant amount of new applications. Digital printing technologies have achieved great success on depositing functional materials to form patterns on flexible substrate, which is essential for flexible electronics development. In this review, we first summrize the unique advantage of digital printing technology over conventional microelectronics and other non-digital based printing methods, like screen printing. Then this article reviews the research and development of digital printing technology for fabriction electronic devices on flexible substrates. Firstly, the printing materials, including conductive materials, semiconductor materials and insulatiing materials, are throughly discussed and different flexible substrates are also reviewed. Then, from reviewing different digital printing techniques, the challenges of implementing flexible electronics into practical application are discussed. Three typical digital printing techniques are discussed, including inkjet printing, electrohydrodynamic printing and aerosol jet printing. Both the limitation and the advantage of digital printing techniques are discussed. One of the major advantages of digital printing is their ability of incorporating the processes into R2R manufacturing process, which is critial for both industry and consumer products, and eliminates the limitation of prototyping application. Thirdly, the related applications of digital printing on the flexible electronic devices are shown. In this review, the key technologies and application of flexible electronics are analyzed, different materials and digital printing technologies, and their applications in 2D/3D printed electronics are shown. Although flexible electronics has achieved great success, the challenges still remain. At the end, some opinions about the development of flexible electronics are raised. The flexiblity, functionality and durablity of flexible electronics still need to be improved in order to provide more practical products into the market.