The increasing demand for portable and ubiquitous electronic applications generated a great interest in the emerging technology area of conformable electronics: a class of materials and electronic devices that are able to adhere and conform to surfaces. Advancements in conformable and stretchable electronics are strongly impacting bioinspired and biointegrated technologies. Notable examples are sensorized and smart electronic skin, novel sensing, actuation and energy-harvesting systems with applications in consumer electronics, energy, robotics, and biomedicine. As regards the development of human–device interfaces— e.g., smart textiles, wearable electronics, and bioelectronics for implantation or unperceivable skin-contact personal health monitoring — their design is focused primarily on portability and comfort to achieve a seamless interaction between user and devices. In this framework, the term “tattoo electronics” or “epidermal electronics” refers to a variety of conformable electronic devices that can be transferred on the skin. From a structural point of view, the use of “soft” materials that imitate the mechanical properties of the skin (suitable elastic moduli), associated with the ultralow thickness of structures, allows for an intimate conformal contact with the nonplanar features and surface irregularities of the skin.