Abstract: A micromechanical pressure relief valve arrangement comprises a stack of wafers. An active pressure relief valve is realized within the stack of wafers. A passive pressure relief valve is also realized within the stack of wafers, arranged in parallel to the active pressure relief valve. A check valve, also realized within the stack of wafers, is arranged in series with both the active pressure relief valve and the passive pressure relief valve.

Abstract: A wafer assembly (30) includes a substrate (71), in turn including a wafer (70) or a stack of wafers. The wafer assembly (30) further includes an electrical connection (32) arranged through at least a part of the substrate (71). The electrical connection (32) is made by low-resistance silicon. The electrical connection (32) is positioned in a hole (84) penetrating at least a part of the substrate (71). A surface (78) of the substrate (71) confining the hole (84) is electrically insulating. The electrical connection (32) has at least one protrusion (75), which protrudes transversally to a main extension (83) of the hole (84) and the protrusion (75) protrudes outside a minimum hole diameter (85), as projected in the main extension (83) of the hole (84). Preferably, the protrusion (75) is supported by a support surface (81) of the substrate (71). A manufacturing method is also disclosed.

Abstract: A nozzle arrangement for use in a gas thruster is presented. At least one heater micro structure (20) is arranged in a stagnation chamber (12) of the gas thruster. The heater microstructure (20) comprises a core of silicon or a silicon compound coated by a surface metal or metal compound coating. The heater microstructure (20) is manufactured in silicon or a silicon compound and covered by a surface metal coating. The heater microstructure (20) is mounted in the stagnation chamber (12) before or after the coverage of the surface metal or metal compound coating. The coverage is performed by heating the heater microstructure and flowing a gas comprising low quantities of a metal compound. The compound decomposes at the heated heater microstructure (20), forming the surface metal or metal compound coating. The same principles of coating can be used for repairing the heater microstructure (20) in situ.

Abstract: A single use valve (10) comprises a plate (12) having an internal filter structure (28). A sealing substance (20) covers an inlet (14) to the filter structure (28). A heater arrangement (16) is arranged at the plate (12) in the vicinity of the sealing substance (20) for converting electrical current into heat and thereby melting or evaporating the sealing substance (20). The heater arrangement (16) conducts at least a part of the current, and preferably the entire current, along a conduction path not including the sealing substance (20). The melting of the sealing substance (20) thereby becomes independent on the existence of a complete electrical connection through the sealing substance (20). The heater arrangement (16) has therefore preferably its main heat emission in an area surrounding the sealing substance (20). The sealing substance (20) can be of any non-porous material.

Abstract: A micromechanical pressure relief valve arrangement (10) comprises a stack of wafers (13). An active pressure relief valve (20) is realized within the stack of wafers (13). A passive pressure relief valve (30) is also realized within said stack of wafers (13), arranged in parallel to the active pressure relief valve (20). A check valve (50), also realized within the stack of wafers (13), is arranged in series with both the active pressure relief valve (20) and the passive pressure relief valve (30).

Abstract: A nozzle arrangement for use in a gas thruster is presented. At least one heater micro structure (20) is arranged in a stagnation chamber (12) of the gas thruster. The heater microstructure (20) comprises a core of silicon or a silicon compound coated by a surface metal or metal compound coating. The heater microstructure (20) is manufactured in silicon or a silicon compound and covered by a surface metal coating. The heater microstructure (20) is mounted in the stagnation chamber (12) before or after the coverage of the surface metal or metal compound coating. The coverage is performed by heating the heater microstructure and flowing a gas comprising low quantities of a metal compound. The compound decomposes at the heated heater microstructure (20), forming the surface metal or metal compound coating. The same principles of coating can be used for repairing the heater microstructure (20) in situ.

Abstract: A wafer assembly (30) includes a substrate (71), in turn including a wafer (70) or a stack of wafers. The wafer assembly (30) further includes an electrical connection (32) arranged through at least a part of the substrate (71). The electrical connection (32) is made by low-resistance silicon. The electrical connection (32) is positioned in a hole (84) penetrating at least a part of the substrate (71). A surface (78) of the substrate (71) confining the hole (84) is electrically insulating. The electrical connection (32) has at least one protrusion (75), which protrudes transversally to a main extension (83) of the hole (84) and the protrusion (75) protrudes outside a minimum hole diameter (85), as projected in the main extension (83) of the hole (84). Preferably, the protrusion (75) is supported by a support surface (81) of the substrate (71). A manufacturing method is also disclosed.

Abstract: A single use valve (10) comprises a plate (12) having an internal filter structure (28). A sealing substance (20) covers an inlet (14) to the filter structure (28). A heater arrangement (16) is arranged at the plate (12) in the vicinity of the sealing substance (20) for converting electrical current into heat and thereby melting or evaporating the sealing substance (20). The heater arrangement (16) conducts at least a part of the current, and preferably the entire current, along a conduction path not including the sealing substance (20). The melting of the sealing substance (20) thereby becomes independent on the existence of a complete electrical connection through the sealing substance (20). The heater arrangement (16) has therefore preferably its main heat emission in an area surrounding the sealing substance (20). The sealing substance (20) can be of any non-porous material.