{
    "title": "Artificial Gills",
    "inventor_name": "Alan-Izhar Bodner",
    "publication_year": null,
    "device_name": "Like-A-Fish Artificial Gill System",
    "goal": "Provide underwater breathing without compressed-air tanks by extracting dissolved air from seawater.",
    "problem_addressed": "Divers are limited by the amount of compressed air they can carry; tanks are bulky, require refills, and limit bottom time.",
    "concept_summary": "The system uses a rapidly rotating centrifuge to create a low-pressure zone inside a sealed chamber containing seawater. The pressure drop causes dissolved gases (oxygen and nitrogen) to come out of solution (Henry's law). The extracted gas is supplied to a closed-circuit rebreather, powered by a rechargeable lithium battery.",
    "detailed_description": null,
    "category": "Mechanical Engineering",
    "principles": [
        "Henry's Law (gas solubility vs. pressure)",
        "Centrifugal pressure reduction",
        "Closed-circuit breathing with CO_2 scrubber"
    ],
    "scientific_domains": [
        "Fluid Mechanics",
        "Chemical Engineering",
        "Thermodynamics",
        "Marine Engineering"
    ],
    "mechanisms_of_action": [
        "Centrifugal pump creates low-pressure core",
        "Dissolved air nucleates and separates from water",
        "Battery powers centrifuge and water pump",
        "CO_2 removal and air recirculation for closed-circuit use"
    ],
    "materials": [
        "Lithium (battery)",
        "Metal alloy (centrifuge housing)",
        "Polymer seals",
        "Seawater (input fluid)"
    ],
    "energy_sources": [
        "Rechargeable lithium battery (electricity)"
    ],
    "inputs": [
        "Sea water",
        "Electrical power from battery"
    ],
    "outputs": [
        "Oxygen-rich breathing gas (~=34 % O_2)",
        "Nitrogen-rich breathing gas"
    ],
    "claimed_performance": "A 1 kg lithium battery can sustain a diver for about one hour; closed-circuit water flow requirement ~=200 L min^-^1; extracted gas enriched to 34 % O_2.",
    "experimental_evidence": "A laboratory model was built and tested in an aquarium, demonstrating that the centrifuge-based extraction principle works in practice.",
    "replication_status": "Prototype (lab model) built and tested by the inventor; no independent replication reported.",
    "keywords": [
        "artificial gills",
        "centrifuge",
        "dissolved oxygen",
        "closed-circuit rebreather",
        "underwater breathing",
        "Like-A-Fish"
    ],
    "related_technologies": [
        "Closed-circuit rebreather",
        "Electrolysis oxygen generators",
        "Artificial gill concepts"
    ],
    "controversy_level": "medium",
    "confidence_score": 0.7,
    "practicability_score": 0.5,
    "fringe_score": 0.6,
    "evidence_strength": 0.5,
    "risk_score": 0.2,
    "trl_estimate": 4,
    "source_urls": [
        "http://www.likeafish.biz",
        "http://en.wikipedia.org/wiki/Like-A-Fish",
        "http://www.isracast.com/articles/63.aspx",
        "http://www.isracast.com/asx/170605b.asx"
    ],
    "organizations": [
        "Like-A-Fish Technologies",
        "Israeli Ministry of Industry and Commerce"
    ],
    "applications": [
        "Scuba diving without tanks",
        "Submarine life-support",
        "Underwater habitats and research stations"
    ],
    "limitations": [
        "High water-flow rates needed for open-circuit use",
        "Battery life limited to ~1 hour with current technology",
        "Size and weight of centrifuge may affect portability",
        "Energy consumption for continuous water processing"
    ],
    "open_questions": [
        "Can the centrifuge be scaled down while maintaining sufficient gas extraction?",
        "What is the long-term reliability of the battery and moving parts underwater?",
        "How will CO_2 removal be integrated efficiently?",
        "How does performance vary with depth and water temperature?"
    ],
    "red_flags": [
        "Claims of indefinite underwater time without refills may be unrealistic.",
        "No independent third-party testing or peer-reviewed data presented."
    ],
    "evidence_quotes": [
        "The system developed by Bodner uses a well known physical law called the \"Henry Law\" which describes gas absorption in liquids.",
        "The system will be powered by rechargeable batteries. Calculations showed that a one kilo Lithium battery can provide a diver with about one hour of diving time.",
        "Bodner has already built and tested a laboratory model and he is on the path to building a full-scale prototype.",
        "We tried it out with water and we saw that in principle it works."
    ]
}