Nanoengineers at the University of California, San Diego, have invented a new breed of bio-inks that allow people to draw sensors onto any surface. Using a regular ballpoint pen, users can draw glucose sensors onto skin, or pollution sensors onto leaves, for example.
The bio-ink contains enzymes that react with specific chemicals. Graphite powder adds conductivity, while chitosan – an antibacterial agent used in bandages – helps the ink adhere to any surface. All the ingredients are non-toxic, making them safe to use on plants and human skin.
The bio-ink offers new possibilities for collecting data from the physical world, according to Joseph Wang, chairman of the university's nanoengineering department, who led the research. "Our new biocatalytic pen technology, based on novel enzymatic inks, holds considerable promise for a broad range of applications on-site and in the field," he said.
The researchers envision the ink could also be used on smartphones as an inexpensive health monitoring service, or on external building walls to measure levels of toxic gasses, for example.
The team is now working on wirelessly connecting the sensors to monitoring devices, and testing their performance under extreme climate conditions.