Solution-processed TiOx layer was investigated as a candidate for next-generation resistive random access memory (ReRAM) application. TiOx active layer was prepared by simple spin coating process of a titanium(IV) isopropoxide precursor using sol-gel chemistry. Through the introduction of indium-tin-oxide (ITO) coated glass and polyethersulfone (PES) substrates. tranparent and flexible ReRAM devices were demonstrated, respectively. In addition, using scalable via-hole structure with nano-scale active area, the feasibility for high-density memory application was investigated. All ReRAM devices formed using various substrates exhibited good memory performance, such as stable dc I-V, ac endurance, and retention characteristics during maintaining their own unique functions accomplished by substrate properties. (C) 2011 Elsevier B.V. All rights reserved.