FLIP: Transforming Consumer Projectors into Maskless Microscale Photopatterning Tools via Fresnel Lens Integration

Photopatterning has emerged as a powerful strategy for precise micropatterning of biomolecules on surfaces due to its high spatial resolution, flexibility, and compatibility with a range of biological materials. Existing photopatterning techniques often rely on expensive, specialized equipment or involve labor‐intensive fabrication processes, limiting their widespread adoption and scalability. Herein, the Fresnel Lens Integrated Projector (FLIP) platform is presented that transforms consumer‐grade projectors into maskless microscale visible‐light photopatterning systems via their integration with a Fresnel lens. FLIP offers a cost‐effective photopatterning solution ($100–$200 USD, <100 cm 2 footprint) that eliminates the need for cleanroom infrastructure or specialized microfabrication, making it accessible for standard laboratories. The compatibility of this approach is demonstrated with both LCD and DMD projection technologies, enabling flexible spectral illumination (450–617 nm) and maskless light modulation on surfaces. The system supports diverse workflows, such as photoreductive silver patterning on halide films (30 µm resolution at 450 nm illumination) and photo‐crosslinking of gelatin methacrylate hydrogels (135 µm resolution at 565 nm illumination) on glass and plastic substrates. This scalable, dynamically configurable platform provides an affordable and flexible solution for applications spanning flexible electronics, biomaterial engineering, and beyond.