Abstract: The present invention provides a proportional microvalve having a first, second and third layer, and having high aspect ratio geometries. The first layer defines a cavity with inlet and outlet ports. The second layer, doped to have a low resistivity and bonded between the first and third layers, defines a cavity having a flow area to permit fluid flow between the inlet and outlet ports. The second layer further defines an actuatable displaceable member, and one or more thermal actuators for actuating the displaceable member to a position between and including an open and a closed position to permit or occlude fluid flow. The third layer provides one wall of the cavity and provides electrical contacts for electrically heating the thermally expandable actuators. The thermal actuators and the displaceable member have high aspect ratios and are formed by deep reactive ion etching such that they are displaceable in the plane of the second layer while being very stiff out of the plane.

Abstract: This invention provides method and apparatus for fabricating a MEMS apparatus having a bulk element with hinges underneath. The bulk element may comprise single-crystal silicon, fabricated by way of bulk micromachining techniques. The hinges may be made of thin-films, fabricated by way of surface micromachining techniques. A distinct feature of the MEMS apparatus of the present invention is that by disposing the hinges underneath the bulk element, the surface of the bulk element can be maximized and the entire surface becomes usable (e.g., for optical beam manipulation). Such a feature would be highly advantageous in making arrayed MEMS devices, such as an array of MEMS mirrors with a high optical fill factor. Further, by advantageously making use of both bulk and surface micromachining techniques, a MEMS mirror thus produced is equipped with a large and flat mirror along with flexible hinges, hence capable of achieving a substantial rotational range at modest electrostatic drive voltages.

Abstract: The present invention provides a proportional microvalve having a first, second and third layer, and having high aspect ratio geometries. The first layer defines a cavity with inlet and outlet ports. The second layer, doped to have a low resistivity and bonded between the first and third layers, defines a cavity having a flow area to permit fluid flow between the inlet and outlet ports. The second layer further defines an actuatable displaceable member, and one or more thermal actuators for actuating the displaceable member to a position between and including an open and a closed position to permit or occlude fluid flow. The third layer provides one wall of the cavity and provides electrical contacts for electrically heating the thermally expandable actuators. The thermal actuators and the displaceable member have high aspect ratios and are formed by deep reactive ion etching such that they are displaceable in the plane of the second layer while being very stiff out of the plane.

Abstract: This invention provides method and apparatus for fabricating a MEMS apparatus having a bulk element with hinges underneath. The bulk element may comprise single-crystal silicon, fabricated by way of bulk micromachining techniques. The hinges may be made of thin-films, fabricated by way of surface micromachining techniques. A distinct feature of the MEMS apparatus of the present invention is that by disposing the hinges underneath the bulk element, the surface of the bulk element can be maximized and the entire surface becomes usable (e.g., for optical beam manipulation). Such a feature would be highly advantageous in making arrayed MEMS device, such as an array of MEMS mirrors with a high optical fill factor. Further, by advantageously making use of both bulk and surface micromachining techniques, a MEMS mirror thus produced is equipped with a large and flat mirror along with flexible hinges, hence capable of achieving a substantial rotational range at modest electrostatic drive voltages.