Multi-Scale Design, Thermal Simulation, Fabrication, Surface Engineering and Characterization of TPMS Structures for Atmospheric Water Generation

The objective of this research is to improve the performance of Atmospheric Water Generators (AWG) by engineering the condensation surface across multiple scales. Specifically, this study explores the use of Triply Periodic Minimal Surfaces (TPMS) as condensation surfaces in Peltier-driven AWG systems—an approach that departs from traditional flat or finned designs. This multiscale engineering strategy integrates macroscale geometry optimization, microscale surface roughness control, and nanoscale analysis of surface coatings and elemental composition. TPMS structures are known for their exceptionally large and complex surface area and are widely used as heat sink. The novelty of this work lies in the introduction of TPMS as a condensation surface for AWG applications, combined with a detailed investigation of all contributing factors from macro- to nanoscale. In this study, they were parametrically modeled and thermally simulated to evaluate their surface area-to-volume ratio and cooling performance to identify the most promising designs. Regression analyses and multi-objective optimization were performed to identify optimal design parameters for each geometry that maximize water collection efficiency. Selected TPMS geometries were prototyped using additive manufacturing and underwent detailed evaluation process, including surface topography, wettability, roughness, and the effects of various surface treatments aimed at enhancing condensation performance. Multiscale materials characterization provided critical insights into how fabrication and post-processing influence surface properties. The engineered TPMS structures were then integrated into a Peltier-based AWG laboratory setup, and their water collection performance was evaluated before and after surface treatments. The results demonstrate that TPMS, when carefully designed and modified, can serve as a viable and innovative alternative to conventional flat or finned surfaces in AWG systems. Notably, the Diamond and Schwarz structures exhibited the highest water collection performance in their untreated state, primarily through film-wise condensation. In contrast, the Gyroid and Lidinoid geometries showed significant performance improvements after surface treatment, enabling efficient dropwise condensation. This research represents a significant engineering milestone by combining insights from geometry design, additive manufacturing, and materials modification to create an integrated, multiscale solution for atmospheric water harvesting. The findings are useful for further advancements in AWG technology and broader applications of TPMS in thermal-fluid systems

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Materials Science, Engineering, and Commercialization

Grantor

Texas State University

Year dc:date.issued

2025

Author dc:creator

• Zohra, Fatema Tuz

Advisor dc:contributor.advisor

• Asiabanpour, Bahram

Committee members dc:contributor.committeemember

• Londa, Michelle
• Emami, Anahita
• Kim, Namwon
• Nguyen, Khoi

• atmospheric water generation (AWG)
• thermal simulation
• triply periodic minimal surfaces
• materials characterization
• surface treatments
• regression analysis
• multi-objective optimization
• additive manufacturing

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10877/22170

OAI identifier oai:identifier

oai:digital.library.txst.edu:10877/22170