Flexible electronics manufacturing technology and equipment

Abstract

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. flexible electronics, micro/nano manufacturing, electrohydrodynamic direct-writing, flip chip, automatic optical inspection

Biogenic amine sensors using organic π-conjugated materials as active sensing components and their commercialization potential

“…Fully printed flexible electronic devices have been under development in recent years, thus all organic electrochemical sensors hold potential for large scale manufacturing via printing methods. [146][147][148] Additionally, many different types of RFID tags are currently mass produced and can be very cost effective, making RFID based sensors very promising candidates for food sensors as the final device can be easily produced by depositing/ printing a small amount of the organic sensing material on a pre-made tag. For chemiresistive sensors, films can be printed and electrodes deposited on top, making this design simple and easy to fabricate.…”

Skin Electrodes Based on TPU Fiber Scaffolds with Conductive Nanocomposites with Stretchability, Breathability, and Washability

“…Therefore, elastomers have been widely utilized in manufacturing stretchable thin-film devices with open mesh designs that possess breathable characteristics [24]. An approach involves embedding metal nanowires into elastomers to manufacture breathable electrodes with deformability [40][41][42][43]. Another advantage of the design is its low mechanical stiffness, facilitating a close connection with highly textured skin [44][45][46].…”

Design, characterization, and performance evaluation of novel PVA/CS/CNF/MOP TN ionic conductive hydrogels for flexible sensors

“…In terms of fabrication techniques, researchers are developing various fabrication techniques to realize the scalability and manufacturability of flexible sensors. These techniques include methods, such as printing, 8 inkjet, 9 solution immersion, 10 and laser processing 11 to achieve large‐area, high‐resolution, and low‐cost flexible sensor fabrication. A lot of researchers have developed new methods to prepare rigid hydrogel materials, such as radiation enhancement, 12,13 construction of multiple networks, 14,15 the introduction of nanocomposites, 16,17 and saline solution immersion 18,19 .…”