Flexible electronics manufacturing technology and equipment

Flexible electronics such as mechanically compliant displays,sensors and solar cells,have important applications in the fields of energy,national defence and biomedicine,etc.Various types of flexible electronics have been proposed or developed by the improvements in structural designs,material properties and device integrations.However,the manufacturing of flexible electronics receives little attention,which limits its mass production and industrialization.The increasing demands on the size,functionality,resolution ratio and reliability of flexible electronics bring several significant challenges in their manufacturing processes.This work aims to report the state-of-art technologies and applications of flexible electronics manufacturing.Three key technologies including electrohydrodynamic direct-writing,flip chip and automatic optical inspection are highlighted.The mechanism and developments of these technologies are discussed in detail.Based on these technologies,the present work develops three kinds of manufacturing equipment,i.e.,inkjet printing manufacturing equipment,robotized additive manufacturing equipment,and roll-to-roll manufacturing equipment.The advanced manufacturing processes,equipment and systems for flexible electronics pave the way for applications of new displays,smart sensing skins and epidermal electronics,etc.By reviewing the developments of flexible electronics manufacturing technology and equipment,it can be found that the existing advances greatly promote the applications and commercialization of flexible electronics.Since flexible electronics manufacturing contains many multi-disciplinary problems,the current investigations are confronted with great challenges.Therefore,further developments of the reviewed manufacturing technology and equipment are necessary to break the current limitations of manufacturing resolution,efficiency and reliability.