This lecture explores the development of soft and permeable electronics for wearable, skin-attached, and implantable applications. It discusses the use of fibrous conductive materials to create flexible, foldable, stretchable, and permeable electronic devices and systems. The importance of permeability for chronic biocompatibility is highlighted, along with the fabrication of high-performance flexible and wearable energy harvesting and storage devices. The evolution of thin-film electronics, the advantages of permeable electronics, and the critical role of permeability for comfort and health are also covered.