Aluminum oxide features good electrical properties such as high dielectric constant and high breakdown voltage. During these last years it has been introduced for the fabrication of metal oxide semiconductor and metal insulator metal capacitors. In the present paper, the mechanical properties of anodic Al2O3 are addressed as well as its interest for microelectromechanical system applications including membranes or cantilevers for humidity, flow, pressure, or biological sensors. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3025906]