Structural layer: the layer of thin film material with which the microstructures are made of. Should have physical and chemical properties that are suitable for the desired application Mechanical properties such as high yield and fracture stresses, minimal creep and fatigue, and good wear resistance

Sacrificial Layer: The layer of material used during the fabrication process to deposit microstructures. These are removed towards the end of the fabrication. So, the layer has no role in the operation of the device. Good mechanical properties so that device does not fail while fabrication Good adhesion Low residual stresses