Contemporary human life relies heavily on mobile devices such as smart-phone, lap-top, or tablet PC which process tremendous amount of information every day. In near future, rapid development of information technology (IT) would eventually integrate the devices as a wearable and flexible form that will collect and process information ubiquitously. For the fabrication of flexible and stretchable devices with high performance and reliability, monolithic integration of inorganic materials and devices in flexible form must be developed. Here we propose that hybrid heterostructures, composed of inorganic nanostructures grown directly on 2-dimentional (2-D) layered materials such as graphene, are the most promising material system for flexible device applications. The inorganic nanostructures in the hybrid nanomaterials exhibit excellent electrical and optical characteristics, including high carrier mobility, radiative recombination rate, and long-term stability. Meanwhile, 2-D layered materials, such as graphene, hexagonal-boron nitride (h-BN), chalcogenides and their hybrids, in the hybrid nanomaterials are flexible, stretchable, and mechanically strong, along with interesting and excellent physical properties. We believe that our unique technology to make hybrid nanomaterials will make paradigm shift from rigid to flexible and planar to three-dimensional inorganic semiconductor structures and devices.