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This paper presents a computer-controlled tilt-rotational UV-laser exposure system for 3D microfabrication. The system incorporates a beam expander to enlarge the beam width of a 405 nm laser diode, which serves as the light source. A computer-controlled sample holder platform utilizes two stepper motors to enable tilting and rotational movements, allowing the creation of complex microstructures using SU-8 photoresist via the lithography process. By implementing various combinations of tilting and rotation, arrays of intricate 3D microstructures, including pillars, angled pillars, horns, and bowties, were successfully fabricated, with feature heights ranging from 20 to 500 μm. The tiltable UV-laser exposure system holds significant potential for applications in 3D microelectromechanical systems (MEMS), such as micro-biosensors and micro-antennas for biomedical and RF applications. 

The precise spatiotemporal control and manipulation of fluid dynamics on a small scale granted by lab-on-a-chip devices provide a new biomedical research realm as a substitute for in vivo studies of host–pathogen interactions. While there has been a rise in the use of various medical devices/implants for human use, the applicability of microfluidic models that integrate such functional biomaterials is currently limited. Here, we introduced a novel dental implant-on-a-chip model to better understand host–material–pathogen interactions in the context of peri-implant diseases. The implant-on-a-chip integrates gingival cells with relevant biomaterials – keratinocytes with dental resin and fibroblasts with titanium while maintaining a spatially separated co-culture. To enable this co-culture, the implant-on-a-chip's core structure necessitates closely spaced, tall microtrenches. Thus, an SU-8 master mold with a high aspect-ratio pillar array was created by employing a unique backside UV exposure with a selective optical filter. With this model, we successfully replicated the morphology of keratinocytes and fibroblasts in the vicinity of dental implant biomaterials. Furthermore, we demonstrated how photobiomodulation therapy might be used to protect the epithelial layer from recurrent bacterial challenges (∼3.5-fold reduction in cellular damage vs. control). Overall, our dental implant-on-a-chip approach proposes a new microfluidic model for multiplexed host–material–pathogen investigations and the evaluation of novel treatment strategies for infectious diseases.