DissolvPCB: Fully Recyclable 3D-Printed Electronics with Liquid Metal Conductors and PVA Substrates

TL;DR

DissolvPCB introduces a fully recyclable 3D-printed PCB technology using water-soluble substrates and liquid metal conductors, enabling easy recycling and reuse of electronic components, with demonstrated functional prototypes.

Contribution

This work presents a novel fully recyclable PCB fabrication method combining 3D printing, water-soluble substrates, and liquid metal conductors, including design software and lifecycle analysis.

Findings

Successful fabrication and recycling of functional prototypes

Lower environmental impact compared to traditional PCBs

Effective software tool for converting designs into printable models

Abstract

We introduce DissolvPCB, an electronic prototyping technique for fabricating fully recyclable printed circuit board assemblies (PCBAs) using affordable FDM 3D printing, with polyvinyl alcohol (PVA) as a water-soluble substrate and eutectic gallium-indium (EGaIn) as the conductive material. When obsolete, the PCBA can be easily recycled by immersing it in water: the PVA dissolves, the EGaIn re-forms into a liquid metal bead, and the electronic components are recovered. These materials can then be reused to fabricate a new PCBA. We present the DissolvPCB workflow, characterize its design parameters, evaluate the performance of circuits produced with it, and quantify its environmental impact through a lifecycle assessment (LCA) comparing it to conventional CNC-milled FR-4 boards. We further develop a software plugin that automatically converts PCB design files into 3D-printable circuit substrate models. To demonstrate the capabilities of DissolvPCB, we fabricate and recycle three functional prototypes: a Bluetooth speaker featuring a double-sided PCB, a finger fidget toy with a 3D circuit topology, and a shape-changing gripper enabled by Joule-heat-driven 4D printing. The paper concludes with a discussion of current technical limitations and opportunities for future directions.