University of Missouri Engineers Develop Draw-On Electronics Using Pencil and Paper

University of Missouri engineers have developed a new tattoo of sorts that would allow people to draw bioelectronic devices, including health monitors and energy harvesters, onto their skin using a pencil and a piece of paper. Many existing commercial skin-based medical devices are comprised of two major components — a biomedical tracking part and a flexible material, such as polymers, to conform to the skin and maintain contact.

Wearable medical devices with direct skin contact typically utilize conductive inks and substrates that are difficult and on the expensive side to produce. Pencils, on the other hand, contain lead, graphite, clay, and wax cost next to nothing, and can be found in nearly every office supply and grocery store. The researchers took notice and discovered that pencils that contain more than 90% graphite could conduct a high amount of energy, caused by friction between paper and pencil while drawing or writing.

That initial finding led them to identify pencils with a 93% graphite content that was ideal for creating a myriad of on-skin bioelectric devices drawn on ordinary office copy paper. They also note that using a spray-on adhesive applied to the paper could help keep it applied to the skin for direct contact. In a recently released paper entitled “Pencil-paper on-skin electronics,” the team states their breakthrough could have a wide range of applications in the future, including home-based personal healthcare, body heat energy generation, education, and remote-based research, such as analyzing diseases to help prevent pandemics. Like temporary tattoos, the pencil/paper-based electronic devices will decompose in about a week, leaving nothing behind.