Some argue that the original Star Trek series predicted the flip phone. Later installments of the franchise used little badges. But Babylon 5 had people talking into a link that stuck mysteriously to the back of their hand. This might turn out to be true if researchers at the University of Minnesota have their way. They’ve modified a common 3D printer to print electronic circuits directly to the skin, including the back of the hand, as you can see in the video below. There’s also a preview of an academic paper available, but you’ll have to pay for access to that, for now, unless you can find it on the gray market.
In addition, the techniques also allowed printing biologically compatible material directly on the skin wound of a mouse. The base printer was inexpensive, an Anycubic Delta Rostock that sells for about $300.
The printer uses a specialized ink that contains silver flakes. It cures at room temperature which is good because you probably don’t want hot plastic burning into the back of your hand. That means the extrusion is more like a paste printer. However, that’s not the main innovation. The primary problem with printing on a person’s body is that people move, even if they try not to.
The new system puts temporary markers on the skin. The printer scans and adjusts its movement to match up with the moving hand or other body parts. Of course, to create really practical electronics, you’ll surely need some components that can’t be printed. In the paper, they show an LED with a 3D printed inductor that can couple to a power source.