The invention provides systems and methods for tissue-mounted electronics and photonics. Devices of some embodiments of the invention implement high performance, and optionally flexible, device components having miniaturized formats in device architectures that minimize adverse physical effects to tissue and/or reduce interfacial stresses when mounted on tissue surfaces. In some embodiments, the invention provides complementary tissue mounting strategies providing for mechanically robust and/or long term integration of the present devices, for example, via mounting on tissue surfaces that are not subject to rapid growth or exfoliation processes such as the fingernail, toenail, tooth or earlobe. Devices of the invention are versatile and support a broad range of applications for sensing, actuating and communication including applications for near field communication, for example, for password authentication, electronic transactions and biometric sensing.