Micromachine friction test apparatus

A friction test apparatus formed on a substrate and comprising:

• (a) a cantilevered driver beam supported at one end thereof above the substrate and substantially co-planar with the substrate;
• (b) an elongate friction pad connected to the other end of the driver beam by a pair of hinges attached to opposite sides of the friction pad;
• (c) a contact pad formed on the substrate below the friction pad;
• (d) a first electrostatic means for providing a vertically-directed force to bring the friction pad into mechanical contact with the contact pad;
• and
• (e) a second electrostatic means for providing a horizontally-directed force to move the friction pad laterally along the contact pad.

An apparatus for assessing friction or wear in microelectromechanical systems, comprising:

• (a) a pair of substantially planar surfaces, with one of the surfaces being stationary, and with the other surface comprising a bottom surface of an elongate friction pad which is moveable in both a vertical direction and a horizontal direction;
• (b) a first electrostatic actuator for applying a vertical-directed force to bring the surfaces into contact with each other, with the first electrostatic actuator comprising a pair of superposed electrodes on each side of the friction pad, with each pair of electrodes further comprising a stationary electrode on the substrate below a moveable electrode attached to the friction pad;
• (c) means for applying a lateral force to produce rubbing motion between the surfaces;
• and
• (d) means for determining a lateral displacement between the surfaces resulting from the rubbing motion.

A microelectromechanical (MEM) fabrication process quality tool, comprising:

• (a) a micromachined cantilevered-beam structure formed on a substrate and further comprising a first substantially planar surface formed above the substrate, and a second substantially planar surface formed as a bottom surface of an elongate friction pad attached to a cantilevered beam, with the second surface being superposed over the first surface, being moveable to contact the first surface, and being moveable laterally relative to the first surface;
• (b) means for applying a vertically-directed force to bring the second surface into contact with the first surface;
• and
• (c) means for applying a horizontally-directed force to move the second surface laterally relative to the first surface, thereby enabling a determination of static or dynamic friction between the first and second surfaces.