Micro hot embossing of thermoplastic polymers is a promising process to fabricate high precision and high quality features in micro/nano scale. This technology has experienced more than 40 years development and has been partially applied in industrial production. Three modes of micro hot embossing including plate-to-plate, roll-to-plate and roll-to-roll have been successively developed to meet the increasing demand for large-area patterned polymeric films. This review surveys recent progress of micro hot embossing in terms of polymeric material behavior, embossing process and corresponding apparatus. Besides, challenges and innovations in mold fabrication techniques are comprehensively summarized and industrial applications are systematically cataloged as well. Finally, technical challenges and future trends are presented for micro hot embossing of thermoplastic polymers.

Owing to their compatibility with biology and large deformation, flexible electronics meet the demands for a wide range of applications that lie outside the capabilities of conventional rigid wafer‐based electronics. Devices such as solar cells, light‐emitting devices, touch screens, and wearable sensors have significantly advanced in recent years and changed human life. Flexible transparent electrodes are one of the most important components in flexible optoelectronic devices, collecting charges and transmitting light. Such electrodes based on silver nanowires (AgNWs), which exhibit superior mechanical flexibility, electrical and thermal conductivity, and optical transparency, are regarded as the most promising alternative to conventional indium tin oxide electrodes. However, some technical challenges, such as the uniformity and stability of AgNW networks, still exist and hinder the large‐scale commercialization of AgNW electrodes. Great efforts have been made in this field. A comprehensive survey of recent progress in flexible transparent AgNW electrodes in terms of performance criteria, material synthesis, fabrication process, performance enhancement, and future applications is provided. Finally, technical challenges and future trends are presented for the application of flexible transparent AgNW electrodes in flexible electronics.

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Surface-enhanced Raman spectroscopy (SERS) has been a powerful tool for applications including single molecule detection, analytical chemistry, electrochemistry, medical diagnostics and bio-sensing. Especially, flexible SERS substrates are highly desirable for daily-life applications, such as real-time and in situ Raman detection of chemical and biological targets, which can be used onto irregular surfaces. However, it is still a major challenge to fabricate the flexible SERS substrate on large-area substrates using a facile and cost-effective technique. The roll-to-roll ultraviolet nanoimprint lithography (R2R UV-NIL) technique provides a solution for the continuous fabrication of flexible SERS substrate due to its high-speed, large-area, high-resolution and high-throughput. In this paper, we presented a facile and cost-effective method to fabricate flexible SERS substrate including the fabrication of polymer nanostructure arrays and the metallization of the polymer nanostructure arrays. The polymer nanostructure arrays were obtained by using R2R UV-NIL technique and anodic aluminum oxide (AAO) mold. The functional SERS substrates were then obtained with Au sputtering on the surface of the polymer nanostructure arrays. The obtained SERS substrates exhibit excellent SERS and flexibility performance. This research can provide a beneficial direction for the continuous production of the flexible SERS substrates.

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