OpenIDS2: A low-cost, 3D-printed, open-source platform for reproducible construction of DNA microarray synthesizers

Oligonucleotide synthesis is a fundamental technology in various fields of life science, including synthetic biology, molecular diagnostics, and biotechnology. In this study, we present OpenIDS2, an open-source, second-generation inkjet-based DNA synthesizer designed to enable flexible and low-cost synthesis in laboratory settings. Built upon the original OpenIDS platform, OpenIDS2 reduces the overall device volume to approximately one-third, integrates all control electronics through a custom-designed printed circuit board (PCB), and improves operational stability and fabrication accessibility via a peristaltic pump-based bulk solution delivery system. Notably, most mechanical components are designed for 3D printing, allowing users to fabricate and assemble the system at low cost using widely available tools. This design significantly enhances reproducibility and global accessibility as an open-source hardware platform. The system supports phosphoramidite chemistry and successfully synthesized 15-mer poly(dT) sequences on CPG-based substrates, which were subsequently analyzed by urea-PAGE and HPLC. OpenIDS2 not only demonstrates the practicality of a fully open, benchtop oligonucleotide synthesizer, but it also serves as a reproducible and extensible foundational platform that lowers the barrier to entry for laboratory automation through its nature as an open-source contribution.