Search for: All records

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. 

Knowing how and when people interact with their surroundings is crucial for constructing dynamic and intelligent environments. Despite the importance of this problem, an attainable and simple solution is still lacking. Current solutions often require powered sensors on monitored objects or users themselves. Many such systems use batteries [1-3], which are costly and time consuming to replace. Some powered systems connect to the grid, which may save swapping batteries, but at the price of restricted placement options. Other solutions use passive tags on monitored objects or require no tags at all, but many of these systems have prohibitive characteristics. For instance, camera-based systems [4,5] generally will not work if their view is occluded. Many other systems that rely on passive tags or do not use tags require direct line-of-sight or close proximity to work. As such, our goal was to design and develop small, cheap, easy-to-install tags that do not require any batteries, silicon chips or discrete electronic components, which can be monitored without direct line-of-sight.