Abstract: A MEMS hysteretic thermal device may have two passive beam segments driven by a current-carrying loop coupled to the surface of a substrate. The first beam segment is configured to move in a direction having a component perpendicular to the substrate surface, whereas the second beam segment is configured to move in a direction having a component parallel to the substrate surface. By providing this two-dimensional motion, a single MEMS hysteretic thermal device may by used to close a switch having at least one stationary contact affixed to the substrate surface.

Abstract: A separated MEMS thermal actuator is disclosed which is largely insensitive to creep in the cantilevered beams of the thermal actuator. In the separated MEMS thermal actuator, a inlaid cantilevered drive beam formed in the same plane, but separated from a passive beam by a small gap. Because the inlaid cantilevered drive beam and the passive beam are not directly coupled, any changes in the quiescent position of the inlaid cantilevered drive beam may not be transmitted to the passive beam, if the magnitude of the changes are less than the size of the gap.

Abstract: A hermetic interconnect is fabricated on a substrate by forming a stud of conductive material over a metallization layer, and then overcoating the stud of conductive material and the metallization layer with a layer of compliant dielectric material. In one embodiment, the layer of compliant dielectric material is low Young's modulus silicon dioxide, formed by sputter-deposition at low temperature, in a low pressure argon atmosphere. The interconnect may provide electrical access to a micromechanical device, which is enclosed with a capping wafer hermetically sealed to the substrate with an AuInx alloy bond.

Abstract: Systems and methods for forming an encapsulated device include a hermetic seal which seals an insulating environment between two substrates, one of which supports the device. The hermetic seal is formed by an alloy of two metal layers, one deposited on a first substrate and the other deposited on the second substrate, along with a raised feature formed on the first or the second substrate. At least one of the metal layers may be deposited conformally over the raised feature. The raised feature penetrates the molten material of the first or the second metal layers during formation of the alloy, and produces a spectrum of stoichiometries for the formation of the desired alloy, as a function of the distance from the raised feature. At some distance from the raised feature, the proper ratio of the first metal to the second metal exists to form an alloy of the preferred stoichiometry.

Abstract: A method for providing access to a feature on a device wafer, and located outside an encapsulation region is described. The method includes forming a cavity in the lid wafer, aligning the lid wafer with the device wafer so that the cavity is located substantially above the feature, and removing material substantially uniformly from the bottom surface of the lid wafer, until an aperture is formed at the cavity, over the feature on the device wafer. By removing material from the lid wafer in a substantially uniform manner, difficulties with the prior art procedure of saw cutting, such as alignment and debris generation, are avoided.

Abstract: A MEMS hysteretic thermal device may have a cantilevered beam which bends about one or more points in at least two substantially different directions. In one exemplary embodiment, the MEMS hysteretic thermal device is made from a first segment coupled to an anchor point, and also coupled to a second segment by a joint. Heating two respective drive beams causes the first segment to bend in a direction substantially about the anchor point and the second segment to bend in a direction substantially about the joint. By cooling the first drive beam faster than the second drive beam, the motion of the MEMS thermal device may be hysteretic. The MEMS hysteretic thermal device may be used for example, as an electrical switch or as a valve or piston.

Abstract: An apparatus for bonding a lid wafer to a device wafer includes an elastic interface having a first surface and a second surface. Relieved areas may be created in the elastic interface by removing at least some of the elastic material of the interface, leaving a mesh with nodes. Raised areas may be disposed on the nodes in staggered positions on the first surface relative to the second surface. The bonding pressure deflects the raised features on the first surface in one direction and the raised features on the second surface in another direction. The restoring force of the mesh transmits the pressure through the interface and to a lid wafer and a device wafer, to bond the lid wafer to the device wafer.

Abstract: Systems and methods for forming an electrostatic MEMS switch include forming a cantilevered beam on a first substrate, forming the electrical contacts on a second substrate, and coupling the two substrates using a hermetic seal. The hermetic seal may be a gold/indium alloy, formed by heating a layer of indium plated over a layer of gold. Electrical access to the electrostatic MEMS switch may be made by forming vias through the thickness of the second substrate.

Abstract: A method for providing improved gettering in a vacuum encapsulated device is described. The method includes forming a plurality of small indentation features in a device cavity formed in a lid wafer. The gettering material is then deposited over the indentation features. The indentation features increase the surface area of the getter material, thereby increasing the volume of gas that the getter material can absorb. This may improve the vacuum maintained within the vacuum cavity over the lifetime of the vacuum encapsulated device.

Abstract: A multiple switch MEMS structure has a higher resistance, higher durability switch arranged in parallel with a lower resistance, less durable switch. By closing the higher resistance, high durability switch before the lower resistance, less durable switch, the lower resistance, less durable switch is protected from voltage transients and arcing which may otherwise damage the lower resistance, less durable switch. By appropriate selection of dimensions and materials, the high resistance, high durability switch may be assured to close first, as well as open first, thereby also protecting the lower resistance, less durable switch from voltage transients upon opening as well as upon closing.

Abstract: A micromechanical actuator for sorting hematopoietic stem cells for use in cancer therapies. The actuator operates by diverting cells into one of a number of possible pathways fabricated in the fabrication substrate of the micromechanical actuator, when fluorescence is detected emanating from the cells. The fluorescence results from irradiating the cells with laser light, which excites a fluorescent tag attached to the cell. The micromechanical actuator thereby sorts the cells individually, with an operation rate of 3.3 kHz, however with the massively parallel 1024-fold device described herein, a throughput of 3.3 million events/second is achievable.

Abstract: A method for forming through hole vias in a substrate uses a partially exposed seed layer to plate the bottom of a blind trench formed in the front side of a substrate. Thereafter, the plating proceeds substantially uniformly from the bottom of the blind hole to the top. To form the through hole, the rear face of the substrate is ground or etched away to remove material up to and including the dead-end wall of the blind hole.

Abstract: A micromechanical particle sorting chip uses an actuator divided into two parts to direct a component of interest into one of a plurality of possible exit paths, based on detection of a fluorescent signal emanating from the component of interest. The two-part actuator may include a force-generating portion and a microactuator portion. The microactuator portion may be disposable, whereas the force-generating portion may be reuseable. By bringing the force-generating portion into proximity to the microactuator portion, the microactuator is induced to move, thereby separating the component of interest from the rest of the fluid stream. The force-generating portion and the microactuator portion may be optimized and fabricated separately, thereby leading to faster, more reliable and less expensive particle sorting.

Abstract: A micromechanical particle sorting chip uses laser light directed through at least one of a reflective and refractive surface to come to a focus in an optically transparent layer. The laser light impinges on a particle of interest, causing it to fluoresce. Upon detecting the fluorescence, a micromemchanical actuator is activated, which directs the particle of interest into one of a plurality of possible exit paths.

Abstract: The invention describes a method and apparatus for deploying micromachined actuators in a plane which is orthogonal to the original fabrication plane of the devices. Using batch-processing, photolithographic procedures known in the micromachined electro-mechanical system (MEMS) art, a plurality of devices is constructed on a suitable substrate. The devices are then separated one from another by sawing and dicing the original fabrication wafer. The devices are rotated into an orthogonal orientation and affixed to a second wafer. The second wafer also contains circuitry for addressing and manipulating each of the devices independently of the others. With this method and apparatus, arrays of actuators are constructed whose plane of actuation is perpendicular to the plane of the array. This invention is useful for constructing N×M fiber optic switches, which direct light from N input fibers into M output fibers.

Abstract: Pressurized fluid from a nozzle is applied against the movable member of a micromechanical device, in order to measure the mechanical properties of the device. The technique is non-destructive, non-invasive, can be applied at the wafer, row or die level, and at early or intermediate stages of fabrication.