This authoritative volume presents a comprehensive exploration of multifunctional epidermal patches, integrating cutting-edge advances in polymer science, bioelectronics, and nanobiotechnology. Edited by Jagan Mohan Dodda, Nureddin Ashammakhi, and Jaeyun Kim, the book systematically covers the synthesis, structural design, and functional characterization of smart patches engineered for real-time diagnostics and targeted therapeutics. Topics include transdermal delivery systems, microneedle arrays, hydrogel matrices, bioresorbable substrates, and self-powered e-skin platforms. Emphasis is placed on the interplay between mechanical compliance, biochemical responsiveness, and electronic integration for applications in wound healing, tissue regeneration, neural and cardiac monitoring, and personalized medicine. With contributions from leading global researchers, this volume serves as a critical reference for materials scientists, biomedical engineers, and clinical innovators seeking to advance the field of wearable theranostic devices.