Lab-on-a-3D-Printer for Democratized Reconfigurable Digital Microfluidics

Automation in the life sciences remains dominated by expensive, centralized robotic systems, leaving most laboratories unable to access precision robotic liquid handling. Here we present the Lab-on-a-3D-Printer (Lo3DP), a reconfigurable robotic microfluidic platform that repurposes the motion control, thermal regulation, and open-source programmability of consumer 3D printers to deliver laboratory-grade automation at a hardware cost below $500. By replacing the extruder with a multifunctional magnetic toolhead, Lo3DP actuates ferrofluid droplets with sub-100 {micro}m positioning accuracy and programmable volume control spanning 0.5-25 {micro}L, enabling the full repertoire of digital microfluidic operations within inexpensive laser-cut chips (<$3). We quantitatively validate system performance through long-term droplet transport exceeding 40,000 s without degradation, automated serial dilutions with high linearity (R{superscript 2} [&ge;] 0.99), and fully automated colorimetric nucleic acid amplification assays whose results match conventional benchtop workflows under tightly regulated isothermal conditions (CV {approx} 0.3%). By harnessing the global economies of scale of consumer 3D printers, Lo3DP provides accurate, reproducible, and programmable assay automation at a fraction of the cost and footprint of conventional systems, establishing a practical path toward desktop-scale, democratized laboratory robotics.