Abstract: A high aspect ratio microelectromechanical system device for measuring an applied force, the device being a cellular in-plane accelerometer formed of a base having a substantially planar mounting surface. A pair of substantially rigid fixed electrode structures are formed in a doped silicon mechanism layer, the fixed electrode structures having substantially parallel and mutually opposing pickoff electrode surfaces oriented substantially perpendicular to the planar mounting surface of the base and spaced apart along an input direction parallel with the planar mounting surface of the base, each of the fixed electrode structures being anchored to the mounting surface of the base. A pendulous electrostatic comb is formed in the doped silicon mechanism layer and oriented substantially perpendicular to the planar mounting surface of the base, the electrostatic comb being pendulously suspended from the mounting surface of the base between the fixed electrode structures for motion along the input direction.