Rapid and Cost-Effective Prototyping of Lab-on-a-Chip Devices Using Maskless UV Exposure and 3D Printing supplementary data

The integration of 3D printing technologies into Lab-on-a-Chip (LOC) fabrication offers a transformative solution for low-cost, flexible, and rapid prototyping of microfluidic biosensing systems. This study presents a 3D UV printing-assisted fabrication strategy for LOC devices designed to detect cardiac troponin I (cTnI), a critical biomarker for myocardial infarction. By repurposing consumer-grade LCD-based 3D printer (Phrozen Sonic Mighty 8K), we enabled maskless UV exposure for biosensor electrode patterning, direct fabrication of microfluidic molds, and construction of complex chip substrates—all without the need for photomasks, UV aligners, or CNC micromachining equipment. Experimental comparisons were conducted between conventionally fabricated devices and 3D-assisted counterparts in terms of electrode fidelity, electrochemical response, channel quality, and surface properties. Cyclic voltammetry and differential pulse voltammetry (DPV) results revealed comparable performance between the two approaches, with the 3D-printed devices maintaining excellent linearity (R² > 0.99) in Randles–Ševčík analysis and achieving sensitive detection of cTnI across a concentration range of 0.1–100 pg/mL. Additionally, contact angle measurements, bonding force tests, and fluidic integrity assessments confirmed the reliability of 3D-printed PDMS channels and printed substrates. Cost analysis highlighted a >75% reduction in per-chip fabrication cost using the 3D print-assisted method compared to conventional protocols, without compromising device performance. These findings demonstrate that consumer-level 3D UV printing offers a practical and scalable pathway for rapid LOC prototyping, especially suited for academic research, point-of-care development, and disease-specific diagnostics such as cardiovascular monitoring.