<p>Wearable physical sensors that measure and monitor human bio-signals and physical activities have attracted increasing attention in recent years for their promising applications including personal healthcare devices, artificial intelligent skins, and soft robotics. These wearable sensors can conformally be attached on the human skin owing to their mechanical flexibility and stretchability with outperforming sensing characteristics. There have been significant research efforts to develop and realize wearable physical sensors in two approaches: functional composite materials and smart structures. Here, recent advances in the development of functional materials and design of smart structures for wearable physical sensors are described. In the first section, functional micro/nano composite materials for various sensing characteristics and novel liquid-phase sensing electrodes with their intrinsic properties are reviewed. Then, smart structures in two- dimensional and three-dimensional forms for unique geometry-induced characteristics are overviewed with representative examples. Lastly, conclusions and prospects of wearable physical sensors are discussed in the final section.</p>