Low-Cost Open Platform Digital Light Printer (OP-DLP) for 96-Well Format Hydrogel Printing and Localized Light-Activation

There is growing demand for high-throughput light-based surface processing methods for applications such as printing hydrogels, controlling cell circuits with light, or activating materials on demand. However, existing devices often fall short for multiwell plate use, require complex synthesis steps, or lack flexibility for general research needs, usually because they are designed for specific tasks. Here, an open-platform digital light printer (OP-DLP) is introduced for easy synthesis of two-dimensional (2D) hydrogels and spatial activation of biomolecules. The device is controlled via a LabVIEW interface that manages printing settings and planar corrections. Importantly, its open platform design enables the use of different wavelengths and compatibility with various printing vessels. Its utility is demonstrated by hydrogel printing and spatial activation of DNA. Specifically, OP-DLP can produce hydrogel layers of precise thickness in a 96-well format with consistent results across the plate. Additionally, OP-DLP can form 2D gels with specific shapes in different wells, allowing modification of ink composition. Its spatial activation capability is demonstrated by the localized de-caging of photocaged DNA on a surface.