One of the key challenges to manufacture low cost circuits on flexible substrates lies in the realization of a reliable gate-dielectric with a high specific capacitance required for low voltage, high current drive. Flexible substrates necessitate deposition techniques with process temperatures lower than 150℃, making the production of high quality gate dielectric materials more difficult.A promising integration scheme for thin film circuits using anodization is demonstrated. Aluminum oxide can be fabricated at low cost by anodization of aluminum at room temperature, giving rise to an ultra-thin, smooth, and dense gate dielectric.Both top-contact and bottom-contact transistors composed with anodized aluminum oxide are demonstrated. The transistors were modified by self-assembled monolayers (SAM), including phenethylchlorosilane (PETS), polyalphamethylstyrene (PαMS) or alkylphosphonic acid (PA). The one modified with PA showed the best performance. The optimized organic transistors had high mobility on both bottom-gate top-contact structure (1.06 cm2/Vs) and bottom-gate bottom-contact structure (0.83 cm2/Vs) and high on/off ratio (ION/IOFF= 108 at VGS= -5 V) for pentacene transistors.Moreover, circuits (inverters and 19 stage ring oscillators) with channel-length down to 3 μm were demonstrated. With the proposed new processing flow, we were able to pattern both gate and gate dielectric simultaneously. This allows us to assess the possibility of using anodized Al2O3 as gate dielectric for TFTs in circuits. Furthermore, integration of an ion sensor with anodized oxideis presented. It is realized by combining a stable In-Ga-Zn-O transistor with anodized oxide. It shows promising scheme for realizing sensors on large area electronics.