We have recently reported high-speed 3D printing of customized optical lenses using projection micro-stereolithography (PμSL) process. However, at the reported printing speed of 24.54 mm3 h-1, it still takes hours for 3D printing an optical lens with the size of millimeter. To further increase the printing speed, we focused on the micro Continuous Liquid Interface Production (μCLIP) process to completely eliminate the time-consuming resin recoating and dwelling steps in PμSL process. While the commonly used oxygen permeable Teflon AF2400 film is found to create rather rough surface of 3D printed structure, we report the use of the home-made Polydimethylsiloxane (PDMS) membrane as the alternative oxygen permeable membrane to overcome this issue. In this study, we demonstrated the significant increased printing speed of 4.85×103 mm3 h-1, which corresponds to a 200-fold improvement in comparison with previously reported PμSL process. We further combined grayscale photopolymerization and meniscus coating steps in the μCLIP process to tackle the inherent speed-accuracy trade-off in 3D printing optical components. We demonstrated the fabrication of an aspherical lens with 1,6-Hexanediol diacrylate (HDDA) using μCLIP system in about 2 minutes. The printed aspherical lens shows impeccable surface finishing, with the surface roughness (RMS=13.7 nm) well below the wavelength of the visible light. It is capable of resolving Element 3 in Group 7 of 1951 USAF resolution test chart, which corresponds to the imaging resolution of 3.10 μm. With significantly improved printing speed, this work unleashes the unprecedented potential of further utilization of 3D printing techniques for rapid manufacturing of novel optical components, such as freeform optics and integrated photonic systems.
Magnetic-driven micro-robotic devices have shown promising potential in enabling applications in micromanipulation, biosensing, targeted drug delivery, and minimally invasive surgery. However, the fabrication of miniaturized magnetic structures with complex geometries has remained the major technical obstacle. In this study, we report the development of a new magnetically-active photopolymerizable resin comprises poly (ethylene glycol) diacrylate monomer, Fe3O4 magnetic nanoparticles, photoinitiator, and other functional additives. Micro-continuous liquid interface production (micro-CLIP) 3D printing process was employed to realize high-resolution and high-speed fabrication of complex structures. The key characteristic properties of resin along with the matching process conditions were investigated experimentally, which allows for establishing the set of optimal fabrication conditions in fabricating magnetic microactuators towards potential applications.