{
  "patent_number": "US 11878818",
  "country": "US",
  "title": "How Tiny Water-Powered Thrusters Steer Small Satellites",
  "original_title": "Tunable water-based microthruster devices and methods",
  "summary": "A method for building microscopic water-based rocket engines that use heat to push water through tiny nozzles to steer small satellites in space.",
  "what_it_does": "This patent describes a way to manufacture extremely small rocket engines, known as microthrusters, for tiny spacecraft. The device works by heating water stored in a small reservoir, which rapidly increases the pressure and forces the water out through a microscopic nozzle throat. The manufacturing process involves etching channels into layers of material—specifically silicon and borosilicate glass—and bonding them together to create the reservoir and nozzle. A key feature is the placement of a heating element that directly contacts the water and is precisely positioned relative to the nozzle throat to ensure efficient propulsion.",
  "what_it_does_not_cover": [
    "Does not cover thrusters that use chemical propellants or combustion rather than water.",
    "Does not cover thrusters with nozzle throat areas larger than 20 square micrometers.",
    "Does not cover propulsion systems that do not use a heating element to create pressure.",
    "Does not cover thrusters where the heating element is not in direct contact with the water."
  ],
  "filed": "2021-09-07",
  "granted": "2024-01-23",
  "expires": null,
  "status": "active",
  "holder": "Purdue Research Foundation",
  "holder_url": "https://patentbrief.org/company/purdue-research-foundation",
  "inventors": [
    {
      "name": "Steven M. Pugia",
      "url": "https://patentbrief.org/inventor/steven-m-pugia"
    },
    {
      "name": "Alina Alexeenko",
      "url": "https://patentbrief.org/inventor/alina-alexeenko"
    },
    {
      "name": "Anthony G. Cofer",
      "url": "https://patentbrief.org/inventor/anthony-g-cofer"
    }
  ],
  "times_cited": 0,
  "tags": [
    "aerospace",
    "semiconductors",
    "mechanical"
  ],
  "abstract": "A microthruster for controlling small spacecraft and methods for manufacturing the same are disclosed. Embodiments of the microthruster include one or more nozzle throats with cross sectional areas of at most 20 μm 2 , and some with 6 μm 2 . Some embodiments include heaters that heat water in one or more reservoirs to increase pressure in the reservoirs and eject the water from the one or more nozzle throats. Some embodiments are manufactured by etching channels into one or more layers of material, and still further embodiments are manufactured by forming the nozzle throats and/or the reservoirs between two layers of material. Some microthruster embodiments are flat in shape with the nozzle throats ejecting water out the thin sides of the microthruster. Still further embodiments are formed by etching channels into one layer of material, printing a heater onto another layer of material, and bonding the two layers together.",
  "url": "https://patentbrief.org/patent/us/11878818/starlink-maritime",
  "markdown_url": "https://patentbrief.org/patent/us/11878818/starlink-maritime/md",
  "google_patents_url": "https://patents.google.com/patent/US11878818",
  "relatedPatents": []
}