What to Do When Good Boards Go Bad

Anyone that has designed printed circuit boards (PCBs) for fun or profit for any length of time undoubtedly has a stack of old, useless boards stuffed away somewhere. In the world of electronics, things rarely go right on the first try. Some signal lines might be inverted, maybe a few passive components were left out of the design, or there could be some issues with electromagnetic interference. Whatever the case may be, it is back to the drawing board to create a new design to send to the fab.

All of those prototypes add up to a lot of e-waste. And since most components are cheap these days, and desoldering them all is not worth the time it takes, they are likely to end up in the trash bin as well. That is a bigger problem than it may seem, because many of these components conceal toxic chemicals within. As they sit in a landfill, these chemicals will leach into the ground and ultimately make their way into water supplies.

PCBs are highly durable and tried-and-true for real-world applications, so we do not want to give them up. But perhaps there is a more suitable technology we could use during the prototyping phase of development. A group led by researchers at the University of Maryland thinks that the solution may be what they call DissolvPCB, which is a fully-recyclable, 3D-printed circuit board. When a design is no longer needed, it can be dissolved in water, allowing all of the components to be salvaged for reuse.

Instead of using FR-4, the industry-standard fiberglass and epoxy laminate that makes recycling difficult, DissolvPCB relies on polyvinyl alcohol (PVA) filament, which is a water-soluble material commonly used in 3D printing. This substrate serves as the structural base for the circuit. To replace copper traces, the researchers inject eutectic gallium-indium, a liquid metal alloy that remains fluid at room temperature, into tiny 3D-printed channels. Components are then slotted into printed sockets and held in place with a special PVA-based glue that doubles as both a mechanical fastener and an electrical sealant.

When the prototype has served its purpose, recycling is simple: just drop the board into a tank of water. The PVA dissolves away, the liquid metal separates into reusable droplets, and the electronic components are freed without the messy process of desoldering. The recovered PVA can even be reprocessed into new 3D-printing filament, meaning virtually all of the material can be looped back into future builds.

To assess the performance of the technology, the researchers tested conductivity, insulation distances, current capacity, and high-frequency signal transmission. While it does not yet rival traditional FR-4 boards in every metric, it performs well enough for prototyping and educational purposes. The team built several demonstration devices — including a Bluetooth speaker, a shape-changing robotic gripper, and a fidget toy with integrated circuitry — to showcase the technology’s potential.

There are limitations to this approach, however. PVA can be tricky to 3D print without clogging, and liquid metal injection requires care to avoid air bubbles and leaks. The technique is not yet suited for high-volume production, and durability lags behind conventional boards. But as a tool for prototyping, it opens a new pathway toward more sustainable electronics. Maybe the answer to our growing e-waste problem is not just better recycling methods, but rethinking the very materials and processes we use when designing electronics in the first place.