Additively manufacturing printed circuit boards with low waste footprint by transferring electroplated zinc tracks

Abstract

Recyclable, degradable and printed electronics are gaining attention as solutions to the growing e-waste problem, but achieving high-resolution, high conductivity circuits with low end-of-life waste footprint remains difficult. Here we show the demonstration of a Printed Circuit Board Assemblies where over 99% of mass degrades into low-toxicity products in controlled or soil environments. Our “growth-and-transfer” process electroplates conductive bulk zinc onto a sacrificial carrier before transfer to a biodegradable substrate. This yields 5 µm track resolution, 3 mΩ/sq sheet resistance, and a shelf life over one year. Performance, lifetime, and degradability were tested, showing rapid degradation in soil under composting conditions. Life Cycle Assessments benchmarked against conventional fibreglass-copper circuit boards reveal a 79% reduction in Global Warming Potential. High-value components, chips, and LEDs are recycled by rinsing in a mild acetic acid solution, with minimal component damage. Our work shows how additive bulk metal growth, benign degradation, and chip recovery could combine to realise high-performance circuit boards with design-for-circularity principles.