Strengthening of micro-cantilever by Au/Ti bi-layered structure evaluated by micro-bending test toward MEMS devicesj

This study reports mechanical property enhancement observed in micro-cantilevers composed of Au/Ti bi-layered structure evaluated by micro-bending test. A layer of gold film is electrodeposited on a cold-rolled titanium plate using a sulfite-based gold electrolyte. Specimens used in the micro-bending test are micro-cantilevers fabricated by focus ion beam from the gold electrodeposited titanium plate, and the dimensions are 50 μm in length, 10 μm in width, and 10 μm in overall thickness. 0.2% yield stresses of micro-cantilevers entirely composed of the cold-rolled titanium and the electrodeposited gold are 324 and 668 MPa, respectively. 0.2% yield stresses of the Au/Ti bi-layered micro-cantilevers are all higher than those of the 100% titanium and 100% gold micro-cantilevers, which confirms the mechanical property enhancement caused by the Au/Ti bi-layered structure. The highest yield stress at 1126 MPa is observed in the Au/Ti bi-layered micro-cantilever composed of 63% gold.