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We report a method of fabricating microstructures directly on a thin β-phase polyvinylidene fluoride (PVDF) film without losing much of its piezoelectricity by employing wet and dry etching technologies. The piezoelectricity of PVDF depends greatly on the temperature, as is generally known. The process conditions, including the PVDF temperature history, were evaluated in experiments where there was almost no change in the PVDF film piezoelectric constant below 60 • C per 4 h. The constant of d 33 in the range above 60 • C per 4 h linearly deteriorated with the rise in temperature by 0.3 × 10 −12 (C N −1 ) • C −1 and at a temperature of 100 • C per 4 h; deterioration of about 50% was confirmed. The N,N -dimethyl acetamide (DMA: C 4 H 9 NO) solution was used as the etchant for wet etching, and O 2 plasma was used for the reactive ion etching (RIE). Tens to a hundred micrometer microstructures were easily fabricated with the proposed approach. The fabrication process technology and experimental results are also reported in detail.

The effect of composition on the pseudobinary ZrCr 2 -NbCr 2 and ZrCr 2 -HfCr 2 Cl5 Laves phase alloys were investigated, focusing upon defect structures and room-temperature fracture toughness. The defect structures were evaluated by lattice parameter and density measurement. The roomtemperature fracture toughness was assessed by Vickers indentation test. Alloying, off-stoichiometry, and related defect structures were shown to be generally beneficial for improving the room-temperature fracture toughness of the Cl5 Laves phases. The results were discussed, based on the local atomic size argument on the most closely packed planes in the C15 Laves phases where shear deformation takes place.

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