Led by Joseph Wang, creator of the non-invasive glucose monitor ApplySci described in January, UCSD engineers are developing “do it yourself” sensors, drawn directly on skin and smartphones. The simple, cheap sensors could be used in the clinic, at home, or on the battlefield.

The bio-inks react with several chemicals, including glucose. Biocompatible polyethylene glycol is used as a binder. Graphite powder makes the inks conductive to electric current. Chitosan ensures that the ink adheres to any surface. Xylitol stabilizes enzymes that react with chemicals the sensors are designed to monitor.

The team filled ballpoint pens with the inks, and drew sensors on the skin to measure glucose, and on leaves to measure pollution. They could be drawn directly on smartphones for cheap, personalized health monitoring, on external building walls for monitoring of pollutants, or on the battlefield to detect explosives and nerve agents.

Wearable Tech + Digital Health NYC 2015 – June 30 @ New York Academy of Sciences