An air moving device includes a film structure, a first actuator and a second actuator. The film structure includes a flap pair, wherein the flap pair includes a first flap and a second flap opposite to each other. The first actuator is disposed on the first flap, and the second actuator is disposed on the second flap. The first actuator includes a first electrode and a second electrode, and the second actuator includes a third electrode and a fourth electrode. The first electrode receives a first demodulation signal and the third electrode receives a second demodulation signal, such that the flap pair performs a differential-mode movement. The second electrode and the fourth electrode receive a modulation signal, such that the flap pair performs a common-mode movement.

A compressor and a multi stack fuel cell are provided with adjustable pressurized fluid inputs. A compressor has a first compressor stage that is configured to take in an intake fluid, compress the intake fluid to a compressed fluid and output the compressed fluid as an output fluid at a first pressure. The compressor further has a second compressor stage that is configured to take in an intake fluid, compress the intake fluid to a compressed fluid, and output the compressed fluid as an output fluid at a second pressure.

A compressor and a multi stack fuel cell are provided with adjustable pressurized fluid inputs. A compressor has a first compressor stage that is configured to take in an intake fluid, compress the intake fluid to a compressed fluid and output the compressed fluid as an output fluid at a first pressure. The compressor further has a second compressor stage that is configured to take in an intake fluid, compress the intake fluid to a compressed fluid, and output the compressed fluid as an output fluid at a second pressure.

A cryogenic pump may include a housing and a drive shaft positioned in the housing. The cryogenic pump may include at least one pump stage positioned in the housing, the at least one pump stage comprising an impeller coupled to the drive shaft. The cryogenic pump may include a balance drum coupled to the drive shaft and positioned in the housing. The cryogenic pump may additionally include a motor comprising a rotor slidably coupled to the drive shaft, the drive shaft configured to rotate with the rotor and move in an axial direction relative to the rotor and the housing during operation of the cryogenic pump.

The present disclosure provides a blower that may increase air volume and reduce blade pass frequency (BPF) noise. The blower may include a plurality of casings and an impeller. The impeller may include a rotator, a blade assembly, and a gasket. The rotator may include a hub and an outer rim. The blade assembly may include: a plurality of blades disposed between the hub and the outer rim, and a plurality of flow channels. Each flow channel of the plurality of flow channels may be formed between two adjacent blades of the plurality of blades. The gasket may have a plurality of grooves formed on an outer circumferential surface of the gasket. The plurality of blades may include a plurality of first blades a plurality of second blades. Each of the plurality of second blades may be disposed between two adjacent blades of the plurality of first blades.

A side channel compressor for compressing a gas includes a housing and at least one impeller which is arranged in the housing and configured to be driven in rotation about a central axis. In addition, the side channel compressor includes at least one seal assembly arranged in the housing and including at least one sealing device configured to seal at least one gap between the housing and the at least one impeller and be forced radially outward with respect to the central axis in order to keep the at least one gap small. The at least one seal assembly also includes at least one sealing-device-holding device configured to hold the at least one sealing device in an axially secured fashion with respect to the central axis and which includes at least one main holding body.

The gas propulsion thrust device comprises a cone-shaped propulsion element with a rigid concave internal surface and a second convex external surface. The propulsion element is submerged in gas and aligned with a high-frequency linear actuator, which causes its reciprocal motion along the longitudinal axis, generating thrust. The device includes a thrust chamber that supports the actuator and surrounds the propulsion element, maintaining a consistent gap between the propulsion element and the chamber to direct gas from the second side to the first side. The chamber tapers around the propulsion element, and a gas directing cap is configured to direct gas around the second side towards the first side. Propulsion element is rigid and its shape remains unchanged during the operation. The reciprocal motion creates a gas pressure differential across the propulsion element, generating thrust by propelling gas away from the propulsion element in the opposite direction of propulsion. The device offers efficient and controlled thrust generation.