(a) Epidermal Electronics. Image of a demonstration platform for multifunctional electronics with physical properties matched to the epidermis. Mounting this device on a sacrificial, water-soluble film of PVA, placing the entire structure against the skin, with electronics facing down, and then dissolving the PVA leaves the device conformally attached to the skin through van der Waals forces, in a format that imposes negligible mass or mechanical loading effects on the skin. (b) Silk-based resorbable wireless heating devices for therapy and drug release. Schematic of the wireless heating device integrated with drug-loaded silk. The heating device comprises a resistor and a wireless coil encapsulated in silk fibroin. Drug molecules loaded in the silk film can be triggered to release under heat treatment for bacterial inhibition. Adapted with permission from refs 20 and 48. Copyright 2011 American Association for the Advancement of Science and 2014 National Academy of Sciences USA.