Sensors for logging human body movements are nothing new, but printing electronic circuits directly onto skin has remained in the realms of science fiction. Until now.
BodyPrinter creates a temporary tattoo-like image on the skin, which can hold surface mount devices (SMDs) to create functional circuitry.
BodyPrinter: Automated Human Circuitry
The machine uses an Arduino Uno with a CNC shield to control a custom-built extruder, small enough to strap to almost any part of the human body. The team made up of KAIST and MIT Media Lab members published a paper on the Association for Computing Machinery Digital Library [PDF], along with a video showing how BodyPrinter works.
The video shows skin mounted circuits used for sensing bends in arms, posture changes, steps taken, and even demonstrates using a finger as a music volume slider. The research team also created a user interface for importing and modifying circuit designs from CAD software.
According to the research paper introducing BodyPrinter, it's designed to complement current adhesive flexible circuitry rather than replace it. At this point, skin printed circuitry is purely research-based, and you won't be buying a BodyPrinter any time soon.
The Dawn of Electronic Tattoos?
A machine that automatically places electronic ink into skin seems like science fiction fodder, and in this case, it is. But only just. While the syringe does make it appear like BodyPrinter penetrates the skin, it actually places a layer of ink on top of it instead. It's far more like a 3D printer than an auto-tattoo gun, though it does have one notable difference.
The human body is very rarely completely flat, so printing on it can be somewhat challenging. The research team gets around this by calibrating BodyPrinter manually over the print area, modifying the Gcode used to account for the varying depth.
Circuits like these have real-world use cases. Body sensing functionality is one of the most popular features of Apple's watchOS, but no smartwatch can give you posture information. Printing strain sensors directly on to the skin will allow movement monitoring down to the smallest human joint.
A Similar Project With a Different Approach
BodyPrinter isn't the only project trying to fuse circuitry with human skin. A recent Penn State News post shares another research team's approach. The project, spanning Penn State, Cheng Lab, and the Harbin Institute of Technology, uses a form of metal sintering combined with a polyvinyl alcohol paste to create metallic circuits directly on human skin.
Printing directly on to skin could see use in both the medical and sports science industries, but it's early days yet. It's going to be some time until you can print your own Electro costume to exact revenge on Spider-Man.
