Dissolvable “transient electronics” may one day allow new capabilities for doctors to monitor their patients, diagnose disease, and offer therapy unlike anything possible with traditional technology. Yet, powering such devices deep inside the body requires a new kind of energy source; one that itself can break up and dissolve into body fluids for eventual excretion. A new battery developed by John A. Rogers, pioneer of flexible and soluble electronics, and team at University of Illinois, Urbana-Champaign, breaks up in water in a matter of weeks.
The four-cell battery consists of magnesium foil anodes and cathodes made of iron, molybdenum, and tungsten, with a phosphate-buffered saline electrolyte in between. The metal ions, at low concentrations, are biocompatible, along with the biodegradable polymer packaging the battery comes in. The team reports that such a battery, one centimeter on the side with an 8 micrometer cathode and 50 micrometer anode produces 2.4 milliamps of electrical current.
Nature News: Biodegradable battery could melt inside the body
Study in Advanced Materials: Materials, Designs, and Operational Characteristics for Fully Biodegradable Primary Batteries