Abstract: One embodiment of a MEMS flow module (34) includes a first plate (36) and a second plate (48) that are separated by a first link (62). A plurality of concentrically disposed, annular flow-restricting walls (40) extend from the first plate (36), and each are separated from the second plate (48) by a flow-restricting gap (58). When the MEMS flow module (34) is exposed to a differential pressure and in one configuration, a perimeter (46) of the first plate (36) flexes away from the second plate (48) (and at least generally about where the first link (62) interfaces with the first plate (36)) to increase the size of one or more of the flow-restricting gaps (58), to in turn accommodate an increased flow or flow rate through the MEMS flow module (34).

Abstract: Various embodiments of MEMS flow modules that regulate flow or pressure by the axial movement of a flow regulating or controlling structure are disclosed. One such MEMS flow module (40) has a regulator (66) that is aligned with and spaced from a first flow port (52) through a first plate (50). The regulator (66) is structurally interconnected with a flexible third plate (80). When the regulator (66) experiences at least a certain differential pressure, the regulator (66) moves at least generally axially away from the first plate (50) by a flexing of the third plate (80) at least generally away from the first plate (50). Increasing the spacing between the regulator (66) and the first plate (50) accommodates an increased flow or flow rate through the MEMS flow module (40).

Abstract: Various embodiments of MEMS flow modules that regulate flow or pressure by the pivoting or pivoting-like movement of a flow regulating or controlling structure are disclosed. One such MEMS flow module (40) has a flow regulating structure (62) including a plurality of baffles (66) and a flow plate (50) including a plurality of flow ports (52). The flow regulating structure (62) also has a support (64) that is spaced from and anchored to the flow plate (50). Each baffle (66) is aligned with at least one flow port (52) and is interconnected to the support (64) of the flow regulating structure (62) in a manner that allows the baffles (66) to flex away from the flow plate (50) based upon the development of at least a certain differential pressure across the MEMS flow module (40).

Abstract: An integral conduit (407) in the formed of stepped tubing defines at least part of a drainage flow path (408/408?) that accommodates a flow rate of at least about 0.15 microliters/minute/mm2/mm-Hg out of the anterior chamber (284) of the eye (266). One or more flow modules (415) may be disposed within this drainage flow path (408/048?) and are located exteriorly of the eye (266). Each flow module (415) may be in the form of a filter or a pressure regulator. In one embodiment, one flow module (415) in the form of a filter is used in combination with another flow module (415) in the form of a pressure regulator.

Abstract: Various embodiments of MEMS flow modules that both filter and regulate pressure are disclosed. One such MEMS flow module (58) has a tuning element (78) and a lower plate (70). A plurality of springs or spring-like structures (82) interconnect the tuning element (78) with the lower plate (70) in a manner that allows the tuning element (78) to move either toward or away from the lower plate (70), depending upon the pressure being exerted on the tuning element (78) by a flow through a lower flow port (74) on the lower plate (70). The tuning element (78) is disposed over this lower flow port (74) to induce a flow through the MEMS flow module (58) along a non-linear (geometrically) flow path. Preferably, a relatively small change in the pressure exerted by this flow on the tuning element (78) produces greater than a linear change in the flow rate out of the MEMS flow module (58).

Abstract: Various embodiments of MEMS flow modules that may be disposed in a flow path (296) of a shunt (290) are disclosed, where the shunt (290) may be used to control a flow out of an anterior chamber (284) of an eye (266). One such MEMS flow module (58) has a tuning element (78) and a lower plate (70). A plurality of springs or spring-like structures (82) interconnect the tuning element (78) with the lower plate (70) in a manner that allows the tuning element (78) to move either toward or away from the lower plate (70), depending upon the pressure being exerted on the tuning element (78) by a flow through a lower flow port (74) on the lower plate (70). The tuning element (78) is disposed over this lower flow port (74) to induce a flow through the MEMS flow module (58) along a non-linear (geometrically) flow path.

Abstract: An implant (98) having an implant filter assembly (92) is disclosed. This implant filter housing (92) is disposed within a passageway (102) of an implant housing (100). One configuration for the implant filter assembly (92) is in the form of a filter assembly (26). The filter assembly (26) includes a LIGA filter element (22) that is disposed between adjacent ends of a first inner housing (34) and a second inner housing (38). These housings (34, 38) are at least partially disposed within an outer housing (30) such that the outer housing (30) is disposed about the LIGA filter element (22). Preferably, at least the outer housing (30) is more rigid than the implant housing (100), at least at a time when the implant (98) is installed in the target biological material.

Abstract: Various MEMS filter elements or modules are disclosed. One such MEMS filter module (34) includes a first film (70) and a second film (46) that are spaced and interconnected by a plurality of supports (78). A plurality of first flow ports (74) extend through the first film (70), and a plurality of second flow ports (50) extend through the second film (46). A plurality of annular filter walls (54) extend from the second film (46) toward the first film (70), and are separated therefrom by a filter trap gap (58). A filter trap chamber (62) is disposed on each side of each filter trap gap (58). Therefore, fluid will flow into one filter trap chamber (62), through a filter trap gap (58), and into another filter trap chamber (62), whether the flow is introduced into the filter module (34) through the first flow ports (74) or the second flow ports (50).

Abstract: Various MEMS filter elements or modules are disclosed, and which may be used in a glaucoma implant (490). One such MEMS filter module (34) includes a first film (70) and a second film (46) that are spaced and interconnected by a plurality of supports (78). A plurality of first flow ports (74) extend through the first film (70), and a plurality of second flow ports (50) extend through the second film (46). A plurality of annular filter walls (54) extend from the second film (46) toward the first film (70), and are separated therefrom by a filter trap gap (58).

Abstract: Various methods for forming surface micromachined microstructures are disclosed. One aspect relates to executing surface micromachining operation to structurally reinforce at least one structural layer in a microstructure. Another aspect relates to executing the surface micromachining operation to form a plurality of at least generally laterally extending etch release channels within a sacrificial material to facilitate the release of the corresponding microstructure.

Abstract: Force transducers are formed of a beam of polysilicon which is mounted at its ends to a silicon substrate and is encapsulated within a polysilicon shell which defines, with the substrate, a cavity around the resonating beam. The cavity is sealed off from the atmosphere and evacuated to maximize the Q of the resonating beam. The beam is produced by deposition of polysilicon in such a way that, combined with subsequent annealing steps, the beam is in zero or low tensile strain. Resonant excitation of the beam may be accomplished in various ways, including capacitive excitation, and the vibratory motion of the beam may be detected utilizing an implanted resistor which is piezoresistive. Formation of the beam is carried out by depositing the beam on a sacrificial layer and surrounding it in a second sacrificial layer before the encapsulating polysilicon shell is formed. The sacrificial layers are etched out with liquid etchant which passes through channels in the periphery of the shell.

Abstract: Force transducers are formed of a beam of polysilicon which is mounted at its ends to a silicon substrate and is encapsulated within a polysilicon shell which defines, with the substrate, a cavity around the resonating beam. The cavity is sealed off from the atmosphere and evacuated to maximize the Q of the resonating beam. The beam is produced by deposition of polysilicon in such a way that, combined with subsequent annealing steps, the beam is in zero or low tensile strain. Resonant excitation of the beam may be accomplished in various ways, including capacitive excitation, and the vibratory motion of the beam may be detected utilizing an implanted resistor which is piezoresistive. Formation of the beam is carried out by depositing the beam on a sacrificial layer and surrounding it in a second sacrificial layer before the encapsulating polysilicon shell is formed. The sacrificial layers are etched out with liquid etchant which passes through channels in the periphery of the shell.

Abstract: Micromechanical structures having surfaces closely spaced from surfaces of a substrate are formed using normal wet etching techniques but are not dried in a conventional manner. While the substrate with the microstructures formed thereon is still wet, the substrate is covered with a liquid that can be frozen, such as deionized water. The liquid on the flooded structure is then frozen in a well controlled manner such that freezing is completed before the microstructure is uncovered. The microstructures are therefore undeflected and are covered by a solid on all surfaces. This solid is then sublimated at a predetermined temperature. Because the frozen liquid (e.g., ice) supports its own surface tension, the microstructures are not drawn toward the substrate, as occurs with the drying of liquids. The sublimation of all the frozen liquid leaves undeflected microstructures with no permanent bonding of the facing surfaces of the microstructure and the substrate.