Fabrication of (K,Na)NbO3 lead-free piezoceramic microrod arrays by sol-gel processing with micromachined silicon templates

A microfabrication process combining sol-gel processing and silicon micromolding was proposed to fabricate microrod arrays of K0.5Na0.5NbO3 (KNN) lead-free piezoelectric ceramics. By ultraviolet lithography and inductively coupled plasma deep reactive ion etching, a Si mold with a regular array of columnar cavities was micromachined, and then filled with KNN sol, followed by pyrolysis and annealing treatment. By optimizing the processing conditions, KNN ceramic microrod arrays of 15 mu m lateral width, 30 mu m height, and 70 mu m spacing were produced, which were identified as perovskite phase structure by X-ray diffraction.