Abstract
The Caldwell-Pulse (GCI #272) is a 2.8 lb (1.27 kg) backpack-portable atmospheric water harvester producing 2.5–4.0 L/day from 10–20% RH desert air. This complete open-hardware release includes:
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Bill of Materials: $254 prototype cost, $99 consumer target (all suppliers listed)
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Step-by-Step Assembly: 4-hour build using 3D printer + makerspace tools
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Test Protocol: DIY desert chamber validation (10% RH, 40°C)
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Performance Targets: 15–20 cycles/day via Cu-NH₂@MOF-303 (0.1 min adsorption), SAW piezo desorption (<2 min), ZnO-cellulose radiative cooling (9.2°C sub-ambient)
Key Advantages: 20x lighter than commercial AWGs, works at 4x lower RH, 200x cheaper. CERN-OHL-P license enables unrestricted humanitarian replication. Every component commercially available today.
Files Included: OpenSCAD Arachne geometry, STL print files, synthesis protocols, test chamber blueprint. Buildable by any engineering team worldwide.
Creative Commons License
CERN-OHL-P (Permissive Hardware License)
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Recommended Citation
Caldwell, Michael Victor Mr., "Caldwell-Pulse: Complete Open-Hardware Atmospheric Water Harvester for Desert Survival (GCI #272)", Technical Disclosure Commons, (April 06, 2026)
https://www.tdcommons.org/dpubs_series/9711