Provided is a method of designing a low-pressure chamber that provides a preset air pressure corresponding to a predetermined altitude. The method may include the steps of: calculating a predetermined error range of the preset air pressure, and calculating an amount and types of materials of a getter to be inserted into the low-pressure chamber based on the error range and a total volume of the low-pressure chamber.

Provided herein are passive microfluidic pumps. The pumps can comprise a fluid inlet, an absorbent region, a resistive region fluidly connecting the fluid inlet and the absorbent region, and an evaporation barrier enclosing the resistive region, the absorbent region, or a combination thereof. The resistive region can comprise a first porous medium, and a fluidly non-conducting boundary defining a path for fluid flow through the first porous medium from the fluid inlet to the absorbent region. The absorbent region can comprise a fluidly non-conducting boundary defining a volume of a second porous medium sized to absorb a predetermined volume of fluid imbibed from the resistive region. The resistive region and the absorbent region can be configured to establish a capillary-driven fluid front advancing from the fluid inlet through the resistive region to the absorbent region when the fluid inlet is contacted with fluid.

Provided herein are passive microfluidic pumps. The pumps can comprise a fluid inlet, an absorbent region, a resistive region fluidly connecting the fluid inlet and the absorbent region, and an evaporation barrier enclosing the resistive region, the absorbent region, or a combination thereof. The resistive region can comprise a first porous medium, and a fluidly non-conducting boundary defining a path for fluid flow through the first porous medium from the fluid inlet to the absorbent region. The absorbent region can comprise a fluidly non-conducting boundary defining a volume of a second porous medium sized to absorb a predetermined volume of fluid imbibed from the resistive region. The resistive region and the absorbent region can be configured to establish a capillary-driven fluid front advancing from the fluid inlet through the resistive region to the absorbent region when the fluid inlet is contacted with fluid.

A cold-atom cell is formed by machining a block of silicon to define sites for an atom source chamber, an atom manipulation chamber, and an ion-pump chamber. A polished silicon panel is frit-bonded to an unpolished (due to machining) chamber wall (which would be difficult and costly to polish). The polished panel can then serve as a reflector or a sight for anodic bonding. A solid-phase atom source provides for vapor phase atoms in the source chamber. The source chamber also includes carbon and gold to regulate the atom pressure by sorbing and desorbing thermal atoms. The atom manipulation chamber includes components for magneto-optical trap and an atom chip, e.g., for forming a Bose-Einstein condensate. The ion-pump chamber serves as the site for an ion pump. By integrating the ion pump into the body of the cold-atom cell, a more compact, reliable, and robust cold-atom cell is achieved. In addition to the embodiment just described, several variations and alternatives are presented and within the scope of the claims.

A cold-atom cell is formed by machining a block of silicon to define sites for an atom source chamber, an atom manipulation chamber, and an ion-pump chamber. A polished silicon panel is frit-bonded to an unpolished (due to machining) chamber wall (which would be difficult and costly to polish). The polished panel can then serve as a reflector or a sight for anodic bonding. A solid-phase atom source provides for vapor phase atoms in the source chamber. The source chamber also includes carbon and gold to regulate the atom pressure by sorbing and desorbing thermal atoms. The atom manipulation chamber includes components for magneto-optical trap and an atom chip, e.g., for forming a Bose-Einstein condensate. The ion-pump chamber serves as the site for an ion pump. By integrating the ion pump into the body of the cold-atom cell, a more compact, reliable, and robust cold-atom cell is achieved. In addition to the embodiment just described, several variations and alternatives are presented and within the scope of the claims.

An electrochemical hydrogen pump includes a hydrogen pump unit including an electrolyte film, an anode catalyst layer, a cathode catalyst layer, an anode gas diffusion layer, an anode separator, a cathode gas diffusion layer, and a cathode separator, a first end plate and a second end plate, a fastener, and a voltage applicator. The electrochemical hydrogen pump transfers and pressurizes hydrogen on the cathode catalyst layer, when a voltage is applied by the voltage applicator. Cathode gas flow channels in which the cathode gas flows are connected to each other. The amount of thickness reduction of the cathode gas diffusion layer due to compression resulting from fastening of the fastener is larger in the hydrogen pump unit positioned at at least one end of the stacked hydrogen pump units than in the hydrogen pump unit positioned at neither end of the stacked hydrogen pump units.

An electrochemical hydrogen pump includes a hydrogen pump unit including an electrolyte film, an anode catalyst layer, a cathode catalyst layer, an anode gas diffusion layer, an anode separator, a cathode gas diffusion layer, and a cathode separator, a first end plate and a second end plate, a fastener, and a voltage applicator. The electrochemical hydrogen pump transfers and pressurizes hydrogen on the cathode catalyst layer, when a voltage is applied by the voltage applicator. Cathode gas flow channels in which the cathode gas flows are connected to each other. The amount of thickness reduction of the cathode gas diffusion layer due to compression resulting from fastening of the fastener is larger in the hydrogen pump unit positioned at at least one end of the stacked hydrogen pump units than in the hydrogen pump unit positioned at neither end of the stacked hydrogen pump units.

Provided herein are passive microfluidic pumps. The pumps can comprise a fluid inlet, an absorbent region, a resistive region fluidly connecting the fluid inlet and the absorbent region, and an evaporation barrier enclosing the resistive region, the absorbent region, or a combination thereof. The resistive region can comprise a first porous medium, and a fluidly non-conducting boundary defining a path for fluid flow through the first porous medium from the fluid inlet to the absorbent region. The absorbent region can comprise a fluidly non-conducting boundary defining a volume of a second porous medium sized to absorb a predetermined volume of fluid imbibed from the resistive region. The resistive region and the absorbent region can be configured to establish a capillary-driven fluid front advancing from the fluid inlet through the resistive region to the absorbent region when the fluid inlet is contacted with fluid.

Provided herein are passive microfluidic pumps. The pumps can comprise a fluid inlet, an absorbent region, a resistive region fluidly connecting the fluid inlet and the absorbent region, and an evaporation barrier enclosing the resistive region, the absorbent region, or a combination thereof. The resistive region can comprise a first porous medium, and a fluidly non-conducting boundary defining a path for fluid flow through the first porous medium from the fluid inlet to the absorbent region. The absorbent region can comprise a fluidly non-conducting boundary defining a volume of a second porous medium sized to absorb a predetermined volume of fluid imbibed from the resistive region. The resistive region and the absorbent region can be configured to establish a capillary-driven fluid front advancing from the fluid inlet through the resistive region to the absorbent region when the fluid inlet is contacted with fluid.

The present invention relates to cathodes electrodes compositions suitable to provide a pumping mechanism which exhibits an extremely high pumping speed and capacity of noble gas suitable to be used in several vacuum devices as for example sputter ion vacuum pumping systems comprising them as active element.