This book provides a comprehensive introduction to printed flexible electronics and their applications, including the basics of modern printing technologies, printable inks, performance characterization, device design, modeling, and fabrication processes. A wide range of materials used for printed flexible electronics are also covered in depth. Bridging the gap between the creation of structure and function, printed flexible electronics have been explored for manufacturing of flexible, stretchable, wearable, and conformal electronics device with conventional, 3D, and hybrid printing technologies. Advanced materials such as polymers, ceramics, nanoparticles, 2D materials, and nanocomposites have enabled a wide variety of applications, such as transparent conductive films, thin film transistors, printable solar cells, flexible energy harvesting and storage devices, electroluminescent devices, and wearable sensors. This book provides students, researchers and engineers with the information to understand the current status and future trends in printed flexible electronics, and acquire skills for selecting and using materials and additive manufacturing processes in the design of printed flexible electronics.