Human body with curved and soft interfaces requests advanced flexible materials and structures for the interaction with organs and signal collection from targets in applications such as bioengineering and diagnostic devices. Among them, it is highly demanded to achieve creative design in flexible materials and structures with great stretchable capability for required applications. To this end, both inorganic and organic materials could be adopted and designed with assembly and self-assembly methods for flexible electronics and electrodes. Soft or flexible materials and structures inspired by nature can lead to highly conformal contacts between devices and the human body. These approaches hold great potential for applications in flexible electronics, medical imaging technology and portable disease diagnostics. Novel strategy on related sensors/actuator and energy storage/generation devices could overcome certain limitations on flexible materials engineering and thus advance the field as well. All these methods would deliver a profound impact to our future intelligent society.