Healthcare must balance safety, efficiency, and effectiveness with affordability and accessibility. Microfluidic devices offer low-cost, portable solutions for point-of-care testing, miniaturizing lab functions on chips through microchannels for quick diagnostics, retaining resolution and sensitivity with minimal reagent use. However, their environmental sustainability is uncertain, with concerns about production scale-up, risks from disposability, and the impact of alternative raw materials or manufacturing techniques compared to traditional soft lithography based on polydimethylsiloxane (PDMS). We conducted a cradle-to-grave life-cycle assessment (LCA) of three glucose-detection devices, a PDMS device via soft lithography, a paper device via wax stamping, and a polylactic acid (PLA) device via 3D printing, for both laboratory-scale and commercial-scale production. For lab-scale production, the paper device had the lowest environmental impact across most impact categories, while the PLA device had the highest. However, for commercial-scale production, by transitioning from 3D printing to injection molding, the PLA device performed best overall, while PDMS performed the worst. For both scales, material and energy use were key contributors, with minimal impact from the use phase. This study highlights the importance of considering environmental impacts at multiple scales and shows the added value of using LCA to guide design and production for early-stage technologies