One such material is PVA (polyvinyl alcohol) - a thermoplast that dissolves when immersed in warm water over the course of a couple of hours.
Transient Devices is an exploratory research project that extends this approach beyond the PCB to the entire electronic device.
As a proof of concept, a game controller was modified to use soluble PVA to reinforce its snap-fit connections. These connections lose their mechanical strength when the material is dissolved, enabling the device to disintegrate when immersed in warm water. This process allows the device to separate into mono-material components: plastics can be sorted by material and color, shred and reused, while most electronic components can be dried and reused or otherwise recycled.