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The complex structures and functional material systems of natural organisms effectively cope with crisis-ridden living environments such as high temperature, drought, toxicity, and predator. Behind these excellent survival strategies evolved over hundreds of millions of years is a series of effective mechanical, optical, hydraulic, and electromagnetic properties. Bionic design and

The complex structures and functional material systems of natural organisms effectively cope with crisis-ridden living environments such as high temperature, drought, toxicity, and predator. Behind these excellent survival strategies evolved over hundreds of millions of years is a series of effective mechanical, optical, hydraulic, and electromagnetic properties. Bionic design and manufacturing have always attracted extensive attention, but the progress has been limited by the inability of traditional manufacturing techniques to reproduce microscopically complex structures and the lack of functional materials. Therefore, there is an urgent need for a fabrication technique with a high degree of fabrication freedom and using composites derived from biological materials. Vat photopolymerization, an emerging additive manufacturing (aka 3D printing) technology, exhibits high manufacturing flexibility in the integrated manufacturing of multi-material systems and multi-scale structures. Here, biomaterial-inspired heterogeneous material systems based on polymer matrices and nanofillers, the introduction of electric field on the basis of conventional 3D printing systems, electrically assisted vat photopolymerization (E-VPP), to spatially and programmably distribute nanofillers are summarized, which provides a new strategy for fabricating anisotropic structures. The application of this versatile 3D printing system in 1) fabricating superhydrophobic structures with controllable micro/nano dual scale surface roughness, 2) dynamically aligning non-conductive nanofiller under electric field using liquid crystal templating, 3) creating hygro-responsive structures with anisotropic gradient porosity, and 4) manufacturing polymer/metal structure in a single step with photocurable heterogeneous material are extensively elaborated.

ContributorsTang, Tengteng (Author) / Li, Xiangjia (Thesis advisor) / Chattopadhyay, Aditi (Committee member) / Phelan, Patrick (Committee member) / Long, Timothy (Committee member) / Jin, Kailong (Committee member) / Kang, Wonmo (Committee member) / Arizona State University (Publisher)
Created2025
Description
This study presents a novel approach to 4D printing by employing surface tension-assisted additive manufacturing to fabricate multi-material structures with tunable surface roughness in response to humidity. Poly(ethylene glycol) diacrylate (PEGDA) was selected as the material due to its hygro-responsive and photocurable properties. The photocurable resin was prepared by varying

This study presents a novel approach to 4D printing by employing surface tension-assisted additive manufacturing to fabricate multi-material structures with tunable surface roughness in response to humidity. Poly(ethylene glycol) diacrylate (PEGDA) was selected as the material due to its hygro-responsive and photocurable properties. The photocurable resin was prepared by varying concentrations of PEGDA, deionized (DI) water, and photoinitiator (PI). The optimized curing and drying times on swelling behavior were studied. The optimal material—mixture of 30 wt% DI water and 0.1 wt% PI—demonstrated the highest swelling ratio while maintaining structural integrity. Vat photopolymerization (VPP) printing method was used to create mesh designs and surface tension-assisted manufacturing was utilized to suspend films of hygro-responsive material. Retentiveness testing showed that circular holes with smaller diameters retained the most material due to uniform tension distribution. The structures exhibited increased surface roughness upon swelling which confirmed the feasibility of the manufacturing methodology. This research suggests the potential for adaptive applications such as responsive grippers or movements with different patterned surface roughness. Future work will focus on improving mechanical properties such as adhesion between different materials and structural brittleness and optimizing fabrication processes through the usage of hydrophobic coatings.
ContributorsYoo, Minju (Author) / Li, Cindy (Thesis director) / Tang, Tengteng (Committee member) / Barrett, The Honors College (Contributor) / Mechanical and Aerospace Engineering Program (Contributor) / The Design School (Contributor)
Created2025-05