Micro-miniature diaphragm pump for the low pressure pumping of gases
First Claim
1. A pump for use in a solid state mass spectrograph for analyzing a sample gas, said mass spectrograph being formed from a semiconductor substrate having a cavity with an inlet, a gas ionizing section adjacent said inlet, a mass filter section adjacent said gas ionizing section and a detector section adjacent said mass filter section, said pump being connected to said cavity, said pump comprising at least one electrically-actuated diaphragm means, said diaphragm means accomplishing a suction stroke upon electrical actuation, whereby said suction stroke evacuates said cavity and draws said sample gas into said cavity wherein said diaphragm means is a bilayer material formed from a resistive metal layer applied on top of a low-stress material, said resistive layer being ohmically heated by passing a current through it, said heated metal layer expanding more than said low-stress material, thereby causing said diaphragm to bend upward.
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Accused Products
Abstract
A pump is provided for use in a solid state mass-spectrograph for analyzing a sample gas. The spectrograph is formed from a semiconductor substrate having a cavity with an inlet, gas ionizing section adjacent the inlet, a mass filter section adjacent the gas ionizing section and a detector section adjacent the mass filter section. The pump is connected to each of the sections of said cavity and evacuates the cavity and draws the sample gas into the cavity. The pump includes at least one diaphragm and electrically-actuated resistor. The resistor generates heat upon electrical actuation thereby causing the diaphragm to accomplish a suction stroke which evacuates the cavity and draws the sample gas into the cavity. Preferably, the diaphragm is formed from a bilayered metal material having different thermal expansion rates or from a shape memory alloy.
297 Citations
11 Claims
- 1. A pump for use in a solid state mass spectrograph for analyzing a sample gas, said mass spectrograph being formed from a semiconductor substrate having a cavity with an inlet, a gas ionizing section adjacent said inlet, a mass filter section adjacent said gas ionizing section and a detector section adjacent said mass filter section, said pump being connected to said cavity, said pump comprising at least one electrically-actuated diaphragm means, said diaphragm means accomplishing a suction stroke upon electrical actuation, whereby said suction stroke evacuates said cavity and draws said sample gas into said cavity wherein said diaphragm means is a bilayer material formed from a resistive metal layer applied on top of a low-stress material, said resistive layer being ohmically heated by passing a current through it, said heated metal layer expanding more than said low-stress material, thereby causing said diaphragm to bend upward.
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11. A pump for use in a solid state mass spectrograph for analyzing a sample gas, said mass spectrograph being formed from a semiconductor substrate having a cavity with an inlet, said pump being connected to said cavity and comprising at least one electrically-actuated diaphragm means, said diaphragm means accomplishing a suction stroke upon electrical actuation, whereby said suction stroke evacuates said cavity and draws said sample gas into said cavity wherein said diaphragm means comprises a bilayer material formed from a resistive metal layer applied on top of a low-stress material, said resistive layer being ohmically heated by passing a current through it, said heated metal layer expanding more than said low-stress material, thereby causing said diaphragm to bend upward.
Specification