Totally organic electrical skin patch powered by flexible biobattery

An electrical skin patch that can be flexibly attached to the skin and activated in 30 s by adding water was developed by integrating a built-in flexible glucose/O2 biobattery. The latter consisted of a glucose dehydrogenase (GDH)-modified anode and an iron(II) phthalocyanine (FePc)-modified cathode. The quick activation of the patch components by water addition deep inside the patch was achieved by using a flexible water-absorbing sponge containing glucose and buffer electrolyte. A patch current of about 10 ìA was maintained for more than 12 h by optimizing the amount of glucose and electrolyte contained in the sponge tank. The entire patch was soft and highly flexible to conform to curved skin surfaces, owing to its thinness (<2 mm) and the flexibility of all the patch components, including the enzyme electrodes based on the carbon fabric.