3D-printed PCB made with liquid metal and PVA is fully recyclable, allows immediate reuse — dissolves and separates when immersed in water, allowing for reuse

A team of researchers from the University of Maryland, Georgia Tech, and the University of Notre Dame created a new 3D printing method for building PCBs that can use fully recyclable materials. That means a PCB can be created, dissolved, and the materials entirely reused to create a new PCB.

According to the paper (via ResearchGate), this technique, called DissolvPCB, utilizes polyvinyl alcohol (PVA) as a printing filament to form a substrate with hollow channels, where eutectic gallium-indium (EGaIn) liquid metal is injected.

The printed circuit board (PCB) can then be immersed in water, where the PVA completely dissolves. It makes it easy to separate the components, allowing the team to reclaim the liquid metal and extract the PVA from the solution for extrusion. This will enable the team to reuse the materials, with recovery rates of up to 99.4% for the PVA and 98.6% for the EGaIn.

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This technique is particularly for experimentation and prototyping, as you don’t have to order or print multiple PCBs for every iteration. It’s also much more sustainable than FR-4 PCBs, which are far more difficult to recycle. These often require a complex, multi-stage process that involves manual dismantling, shredding, and crushing, as well as the use of hazardous chemicals and high temperatures for treatment.