A micro fluid actuator includes an orifice layer, a flow channel layer, a substrate, a chamber layer, a vibration layer, a lower electrode layer, a piezoelectric actuation layer and an upper electrode layer, which are stacked sequentially. An outflow aperture, a plurality of first inflow apertures and a second inflow aperture are formed in the substrate by an etching process. A storage chamber is formed in the chamber layer by the etching process. An outflow opening and an inflow opening are formed in the orifice layer by the etching process. An outflow channel, an inflow channel and a plurality of columnar structures are formed in the flow channel layer by a lithography process. By providing driving power which have different phases to the upper electrode layer and the lower electrode layer, the vibration layer is driven to displace in a reciprocating manner, so as to achieve fluid transportation.

A sensor assembly including a capacitive sensor, like a microelectromechanical (MEMS) microphone, and an electrical circuit therefor are disclosed. The electrical circuit includes a first transistor having an input gate connectable to the capacitive sensor, a second transistor having an input gate coupled to an output of the first transistor, a feedforward circuit interconnecting a back-gate of the second transistor and the output of the first transistor, and a filter circuit interconnecting the output of the first transistor and the input gate of the second transistor.

An acoustic sensor (e.g., for use in a piezoelectric MEMS microphone) includes a substrate and a cantilever beam attached to the substrate. The cantilever beam has a proximal portion attached to the substrate and extends to a distal tip at a free end thereof. The cantilevered beam has a multilayer structure with a plurality of piezoelectric layers and a plurality of metal electrode layers, at least a portion of one of the piezoelectric layers interposed between two metal electrode layers. One or more direct current voltage sources are electrically connected to one or more of the plurality of metal electrode layers and configured to apply a direct current bias voltage between at least two of the plurality of metal electrode layers to deflect the cantilever beam to at least partially counteract a deflection of the cantilever beam due to a residual stress in the cantilever beam.

A method of making an acoustic sensor (e.g., a piezoelectric sensor for a piezoelectric microelectromechanical systems microphone) includes forming or depositing one or more piezoelectric layers to define a beam extending between a proximal portion and a distal tip (e.g., unsupported free end), the beam having a width in plan view that is greater at a location distal of the proximal portion than at the proximal portion. The method also comprises attaching the beam to a substrate in cantilever form so that the proximal portion of the beam is anchored to the substrate and the distal tip is a free unsupported end of the beam. One or more electrodes are disposed on or in the proximal portion of the beam.

A MEMS microphone includes a substrate having an opening, a first diaphragm, a first backplate, a second diaphragm, and a backplate. The first diaphragm faces the opening in the substrate. The first backplate includes multiple accommodating-openings and it is spaced apart from the first diaphragm. The second diaphragm joints the first diaphragm together at multiple locations by pillars passing through the accommodating-openings in the first backplate. The first backplate is located between the first diaphragm and the second diaphragm. The second backplate includes at least one vent hole and it is spaced apart from the second diaphragm. The second diaphragm is located between the first backplate and the second backplate.

According to one embodiment, a sensor includes a base body, a first supporter fixed to the base body, and a first movable part separated from the base body. The first movable part includes a first movable base part supported by the first supporter, a second movable base part connected with the first movable base part, and a first movable beam. The first movable beam includes a first beam, a first movable conductive part, and a first connection region. The first beam includes a first beam portion, a second beam portion, and a third beam portion between the first beam portion and the second beam portion. The first beam portion is connected with the first movable base part. The second beam portion is connected with the second movable base part. The first connection region connects the third beam portion and the first movable conductive part.

A MEMS pump includes a first substrate, a first oxide layer, a second substrate, a second oxide layer, a third substrate and a piezoelectric element sequentially stacked to form a modular structure. The first substrate has an inlet aperture. The first oxide layer has at least one fluid inlet channel and a convergence chamber. One end of the fluid inlet channel is in communication with the convergence chamber and the other end of the fluid inlet channel is in communication with the inlet aperture. The second substrate has a through hole misaligned with the inlet aperture and in communication with the convergence chamber. The second oxide layer has a gas chamber with a concave central portion. The third substrate has a plurality of gas flow channels misaligned with the through hole. The modular structure has a length, a width and a height.

A micro-electro-mechanical system (MEMS) microphone is provided. The MEMS microphone includes a substrate, a backplate, an insulating layer, and a diaphragm. The substrate has an opening portion. The backplate is disposed on a side of the substrate, with protrusions protruding toward the substrate. The diaphragm is movably disposed between the substrate and the backplate and spaced apart from the backplate by a spacing distance. The protrusions are configured to limit the deformation of the diaphragm when air flows through the opening portion.

A microelectromechanical system (MEMS) transducer includes a substrate and a pair of electrodes supported by the substrate. The pair of electrodes are configured as a bias electrode-sense electrode couple. A moveable electrode of the pair of electrodes is configured for vibrational movement in a first direction during excitation of the moveable electrode. The pair of electrodes are spaced apart from one another by a gap in a second direction perpendicular to the first direction. The moveable electrode includes a cantilevered end, the cantilevered end being warped to exhibit a resting deflection along the first direction.

A microfabricated structure includes a perforated stator; a first isolation layer on a first surface of the perforated stator; a second isolation layer on a second surface of the perforated stator; a first membrane on the first isolation layer; a second membrane on the second isolation layer; and a pillar coupled between the first membrane and the second membrane, wherein the first isolation layer includes a first tapered edge portion having a common surface with the first membrane, wherein the second isolation layer includes a first tapered edge portion having a common surface with the second membrane, and wherein an endpoint of the first tapered edge portion of the first isolation layer is laterally offset with respect to an endpoint of the first tapered edge portion of the second isolation layer.