All-polymer thermo-optic (TO) waveguide switch arrays at 650-nm wavelength based on novel organic-inorganic grafting poly(methyl methacrylate) (PMMA) materials are successfully designed and fabricated. The thermal stability and optical properties of the sol-gel materials are studied. The TO coefficient of organic-inorganic grafting PMMA core material is obtained as -1.65×104 °C-1. The characteristic parameters of the embedded waveguide and arrayed electrode heaters are carefully designed and simulated. The propagation loss of a 4-μm wide straight waveguide is 0.85 dB cm-1. The M-Z interferometer TO switch on-off time is 600 μs. The extinction ratio is ~ 8.2 dB and the applied electric power as the switching power is ~ 22.6 mW. The device could have great potential in biomedical applications. The technique could be well suited for polymer optical fiber integrated network systems.