Engineers from Iowa State University and the Ames Laboratory have created a way to print metal on soft and delicate materials. Just how soft and delicate? They printed metal traces on a rose petal and even Jello.
The researchers created an undercooled metal technology that uses a liquid metal trapped below its melting point in tiny oxide shells. The particle, or shell, is about 10 microns in diameter and filled with the metal using a tungsten microprobe. When they crack the shell, the metal flows out, solidifies, and creates/prints conductive, metal lines.
The little shells can be cracked using mechanical pressure or by dissolving it chemicals.
The metal is a Field’s metal, an alloy of bismuth, indium, and tin, and it has created conductive lines on everything from concrete to a leaf.
The technology could soon be used in some exciting applications, such as sensors that monitor building integrity, monitor crop performance, or even medical conditions.
In recent tests, engineers made a remote control on a piece of curved paper, created electrical contacts for solar cells and even printed on a model of a brain. Who needs Neuralink’s brain sewing machine, when you can just crack a few microscopic metal eggs over your grey matter?
The team recently described the technology in the journal Advanced Functional Materials.
The project started three years ago as a teaching exercise, and now the researchers are trying to think of what to print on next – they have suggested ice cubes and biological tissue. Let’s hope they start with a less critical tissue, something like a finger or pinkie toe, and not the brain.