Light-based 3D printing of stimulus-responsive hydrogels for miniature devices: recent progress and perspective

Abstract Miniature devices comprising stimulus-responsive hydrogels with high environmental adaptability are now considered competitive candidates in the fields of biomedicine, precise sensors, and tunable optics. Reliable and advanced fabrication methods are critical for maximizing the application capabilities of miniature devices. Light-based three-dimensional (3D) printing technology offers the advantages of a wide range of applicable materials, high processing accuracy, and strong 3D fabrication capability, which is suitable for the development of miniature devices with various functions. This paper summarizes and highlights the recent advances in light-based 3D-printed miniaturized devices, with a focus on the latest breakthroughs in light-based fabrication technologies, smart stimulus-responsive hydrogels, and tunable miniature devices for the fields of miniature cargo manipulation, targeted drug and cell delivery, active scaffolds, environmental sensing, and optical imaging. Finally, the challenges in the transition of tunable miniaturized devices from the laboratory to practical engineering applications are presented. Future opportunities that will promote the development of tunable microdevices are elaborated, contributing to their improved understanding of these miniature devices and further realizing their practical applications in various fields. Graphic abstract