Micro miniature refrigerators
AssigneeThe Board of Trustees of the Leland Stanford Junior University
InventorWilliam A. Little
Life of this patent
Estimating the term…
Abstract
A microminiature cryogenic device for cooling in the milliwatt range includes a miniature refrigerator in which micron-sized fluid passages are defined in one or more internal surfaces of a laminate of glass or similar low thermal conductivity members by means of lithographic, etching or particle blasting techniques.
Claims26
A compact refrigerator comprising a plurality of plate or platelike members all of materials having substantially the same coefficient of thermal expansion, means bonding said members together in sealed pressure-tight surface contact into a laminated structure and means forming in said structure a low-temperature chamber connected with input and output fluid ports by respective supply and return fluid passages, said supply passage being adapted for conducting incoming highly compressed gas and including a capillary or porous section leading into the cooling chamber whereby the incoming high-pressure gas is allowed to expand and reduce in temperature before entering said chamber, and said return passage having a section extending substantially coextensively in heat exchange relation adjacent at least part of said supply passage, and means whereby said chamber may be in heat exchange contact with a device to be cooled.
A microminiature cryogenic refrigerator for cooling superconductor devices and the like comprising at least two members of materials having substantially the same coefficient of thermal expansion, means bonding said members together in pressure-tight contact over an interface area to provide a stiff laminate and means forming in said laminate a low-temperature chamber connected with an input fluid port by a micron-sized supply fluid passage along said interface area, said supply passage comprising a first section for conducting incoming highly compressed gas and a serially connected smaller diameter second capillary section opening into said chamber whereby the high-pressure gas is allowed to expand and reduce in temperature before entering said chamber, and a return passage having a section extending through the laminate substantially coextensively in counterflow heat exchange relation with said first section of said supply passage, and means whereby said chamber may be in heat exchange contact with a device to be cooled.
A miniature refrigerator comprising a substrate having a confining surface, a planar member having a surface including a pattern formed thereon, said pattern defining a heat exchanger and a reservoir interconnected with said heat exchanger, said substrate and said planar member being cooperatively positioned with said pattern abutting said confining surface thereby forming refrigerant lines, and an input port and an output port interconnected with said heat exchanger for providing a refrigerant flow through said heat exchanger to said reservoir.
A multiple unit miniature refrigerator providing cascade cooling comprising means defining two separate micron-sized fluid inlet passageways in a glass plate laminate, one of said passageways extending from a first input port through a first heat exchange section and a first capillary section in series to a first cooling chamber, and the other of said passageway extending from a second inlet port through a second heat exchange section disposed in heat exchange relation with said first heat exchange section and then serially through a third heat exchange section and a second capillary section to a second cooling chamber, and means providing separate return passageways in said laminate for conducting low-pressure fluid from each said chamber to separate outlet ports, the return passage from said first chamber extending in heat exchange relation to said first and second heat exchange sections, and said return passage from said second chamber extending in heat exchange relation with said third and second heat exchange sections.
Dependencies are inferred from the claim text.