INTEGRATED MOVABLE MICROMECHANICAL STRUCTURES FOR SENSORS AND ACTUATORS

Movable pin-joints, gears, springs, cranks, and slider structures with dimensions measured in micrometers have been fabricated using silicon microfabrication technology. These micromechanical structures, which have important transducer applications, are batch-fabricated with an IC-compatible process. The movable mechanical elements are built on layers that are later removed so that they are freed for translation and rotation. An undercut-and-refill technique which makes use of the high surface mobility of silicon atoms undergoing chemical vapor deposition, is used to refill undercut regions in order to form restraining flanges. Typical element sizes and masses are measured in micro meters and nano grams. The process provides the tiny structures in an assembled form avoiding the nearly impossible challenge of handling such small elements individually.