An operable membrane device is provided, including a plate, a plurality of membranes suspended from the plate and being a seat of residual mechanical constraints, at least a first actuator configured to deform the plate outside its plane, second actuators, each second actuator being configured to deform a membrane outside its plane, and control electronics configured to generate second control signals at the second actuators in order to vibrate the membranes and configured to generate first control signals at the first actuator to cause a deformation of the plate so that the plate is found in the deformed state, wherein a mechanical constraint is applied to the membranes that at least reduces the residual constraints of the membranes.

A valve disposed at a flow path includes: a substrate having a first surface in which a hole having an opening section is formed; and a diaphragm member fixed to at least part of a wall surface of the hole and in which at least a central portion has a thin film shape, wherein a flow of a fluid in the flow path is controlled by deforming the diaphragm member.

A compressing diaphragm pump with multiple effects includes an eccentric roundel mount with three cylindrical eccentric roundels, a pump head body with three operating holes, and a diaphragm membrane with three annular positioning protrusions. A basic curved groove or other positioning structure is circumferentially disposed around each operating hole while a basic curved protrusion or other mating positioning structure is provided in the diaphragm membrane for suitably coupling with the corresponding groove or positioning structure in the pump head body upon assembly, resulting in a shortened length of moment arm from the basic curved protrusions or other positioning structures and an annular positioning protrusion, and a reduction in vibration-caused noise and resonant shaking in comparison with a conventional compressing diaphragm pump. The cylindrical eccentric roundels each includes a sloped top ring extending between an annular positioning groove and a vertical or inverted frustoconical flank of the eccentric roundel mount resulting in an extended service lifespan of the compressing diaphragm pump.

Certain aspects of the present disclosure provide a surgical cassette configured to engage a first plurality of rollers of a first roller head. The cassette comprises a face coupled to a first substrate, the face being at a first angle with respect to the first roller head's axis of rotation and a wall of first substrate being at a second angle with respect to the axis of rotation, wherein the first angle is different from the second angle. The cassette also comprises a first sheet positioned on the wall's surface, wherein the first sheet and the wall form first one or more pump segments configured to engage the first plurality of rollers in a position where force applied by each one of the first plurality of rollers on the first one or more pump segments has a direction that is not parallel to the first roller head's axis of rotation.

An apparatus for compressing a fluid has a linear compression chamber with a fluid inlet and a fluid outlet. A displacement assembly is spaced from the linear compression chamber and is actuable to engage the linear compression chamber and displace a working fluid linearly in the linear compression chamber to decrease the volume of a fluid in the linear compression chamber.

A miniature air pump includes a motor unit, a valve unit and a compression unit. The compression unit is driven by the motor unit to input or output airflows via the valve unit. The compression unit includes an air chamber module and a linkage rod. The air chamber module includes a plurality of compressible chambers and a plurality of resilient connection members, each resilient connection member is located on each compressible chamber. The linkage rod is connected with the motor unit and includes a central rod and multiple sleeves extending from the central rod. Each sleeve has a side cutout. Each resilient connection members engages each sleeve via the side cutout such that the motor unit drives the air chamber module to be compressed or decompressed to input or output airflows via the valve unit. A longitudinal direction of the side cutout is in parallel with the central rod.

A membrane system comprising a membrane and connecting elements for connecting the membrane to a membrane pump for conveying a fluid, which membrane pump has a drive shaft designed for an oscillating translatory movement perpendicular to the plane of the membrane during operation of the membrane pump and has an external thread at an end portion for engagement with the membrane system by screwing. To ensure a secure and torque-proof connection between the membrane and the connecting element to be screwed to a drive shaft, the connecting elements comprise a threaded socket, a thrust ring and a thrust plate.