Epidermal electrochemical devices, including biosensors and biofuel cells, have received considerable attention in the fields of wearable devices and mobile health. A challenge unique for realizing such wearable electrochemical devices is mechanical resiliency. Mechanical damage-induced device failure is a common occurrence that can limit the operational lifespan of wearable bioelectronic devices. Recognizing these issues and challenges, this presentation will describe the use of advanced materials for imparting remarkable stretchability and self-healing abilities that enable epidermal bioelectronic devices to endure extreme deformations experienced by the human skin without compromising their bioelectronic characteristics. Particular attention will be given specially-engineered inks for creating printable electrochemical biosensors and biofuel cells that can endure strains as high as 500% and offer autonomous healing ability without impacting their sensing or energy-harvesting ability.