A5063699801- Polymer composites and self-healing
- Electrospun Nanofibers in Biomedical Applications
- Advanced Sensor and Energy Harvesting Materials
- Surface Modification and Superhydrophobicity
- Mechanical Behavior of Composites
- Advanced Materials and Mechanics
- Flame retardant materials and properties
- biodegradable polymer synthesis and properties
- Heat Transfer and Optimization
- Advanced Polymer Synthesis and Characterization
- Structural Analysis of Composite Materials
- Optical measurement and interference techniques
- Topology Optimization in Engineering
- Cellular and Composite Structures
- Epoxy Resin Curing Processes
- Thermal properties of materials
- Advanced Antenna and Metasurface Technologies
- Industrial Vision Systems and Defect Detection
- Microbial Applications in Construction Materials
- Polymer Nanocomposites and Properties
- Electromagnetic wave absorption materials
- Additive Manufacturing and 3D Printing Technologies
- Advanced Cellulose Research Studies
- Polydiacetylene-based materials and applications
- Photopolymerization techniques and applications
North Carolina State University
2019-2024
University of Illinois Urbana-Champaign
2011-2017
By incorporating 3D microvascular networks containing a two-part reactive chemistry within fiber-reinforced composite, continuous cycles of self-healing after interlaminar delamination are achieved. An interpenetrating vasculature shows improved in situ fluid mixing over segregated microchannels, resulting full recovery (>100%) mode-I fracture resistance.
and materials or lack of scalability vascular complexity the fabrication approach. Here we show that introduction sacrificial fibers into woven preforms enables seamless 3D microvascular composites are both strong multifunctional. Underpinning method is efficient thermal depolymerization catalyst-impregnated polylactide (PLA) with simultaneous evaporative removal resulting lactide monomer. The hollow channels produced high-fidelity inverse replicas original fiber’s diameter trajectory. has...
This letter proposes a concept for frequency-reconfigurable slot antennas enabled by pressure-driven capacitive microfluidic switches. The switches are operated pneumatically displacing plug of eutectic gallium indium alloy (EGaIn) within an air-filled microchannel that traverses the orthogonally. Frequency reconfigurability is achieved altering displacement conductive fluid channel, which reactively loads slot. A transmission-line model developed to capture physical behavior and...
Complex multidimensional vascular polymers are created, enabled by sacrificial template materials of 0D to 3D. Sacrificial material consisting the commodity biopolymer poly(lactic acid) is treated with a tin catalyst accelerate thermal depolymerization, and formed into templates across multiple dimensions spanning several orders magnitude in scale: spheres (0D), fibers (1D), sheets (2D), 3D printed. Templates embedded thermosetting polymer removed using treatment process, vaporization...
When heated, poly(lactic acid) (PLA) fibers depolymerize in a controlled manner, making them potentially useful as sacrificial for microchannel fabrication. Catalysts that increase PLA depolymerization rates are explored and methods to incorporate into commercially available by solvent mixture impregnating technique tested. In the present study, most active catalysts identified capable of lowering temperature modified ca. 100 °C compared unmodified ones. Lower temperatures allow be removed...
Liquid metals adhere to most surfaces despite their high surface tension due the presence of a native gallium oxide layer. The ability change shape functional fluids within three-dimensional (3D) printed part with respect time is type four-dimensional printing, yet adhesion limits pump liquid in and out cavities channels without leaving residue. Rough prevent adhesion, but methods roughen are difficult or impossible apply on interior parts. Here, we show that silica particles suspended an...
Critical to finite element (FE) analysis of fiber-reinforced composites is accurately reproducing microstructural features via high-quality meshes such that the material heterogeneity and anisotropy are properly captured. Here we present an integrated computational framework for generating realistic FE models woven with high fiber volume fractions (>50%). This relies on a virtual microstructure reconstruction algorithm first generates geometric model loosely-woven yarns (i.e., bundles...
Natural processes continuously degrade a material's performance throughout its life cycle. An emerging class of synthetic self-healing polymers and composites possess property-retaining functions with the promise longer lifetimes. But sustained in-service repair structural fiber-reinforced remains unfulfilled due to material heterogeneity thermodynamic barriers in commonly cross-linked polymer-matrix constituents. Overcoming these inherent challenges for mechanical self-recovery is vital...
The maximum volume that can be restored after catastrophic damage in a newly developed regenerative polymer system is explored for various mixing, surface wetting, specimen configuration, and microvascular delivery conditions. A two‐stage healing agent implemented to overcome limitations imposed by tension gravity on liquid retention within volume. formulated as two‐part which the two reagent solutions are delivered through‐thickness, cylindrical defect geometry parallel channels thin epoxy...
Microwave absorbing materials for high-temperature harsh environments are highly desirable aerodynamically heated parts and engine combustion induced hot spots of aircrafts. This study reports ceramic composites with excellent stable microwave absorption in air, which made polymer-derived SiOC reinforced core-shell nanophase structure ZrB2/ZrO2. The fabricated have a crystallized t-ZrO2 interface between ZrB2 domains. exhibit dielectric properties, relatively insensitive to temperature...
Abstract Nearly all‐natural and synthetic composites derive their characteristic attributes from a hierarchical makeup. Engineered metamaterials exhibit properties not existing in natural by precise patterning, often periodically on size scales smaller than the wavelength of phenomenon they influence. Lightweight fiber‐reinforced polymer composites, comprising stiff/strong fibers embedded within continuous matrix, offer superior structural platform for micro‐architectured metamaterials. The...
Abstract Microvascular materials containing internal microchannels are able to achieve multi-functionality by flowing different fluids through vasculature. Active cooling is one application protect structural components and devices from thermal overload, which critical modern technology including electric vehicle battery packaging solar panels on space probes. Creating thermally efficient vascular network designs requires state-of-the-art computational tools. Prior optimization schemes have...
Abstract Modulating temperature fields is indispensable for advancing modern technologies: space probes, electronic packing, and implantable medical devices, to name a few. Bio-inspired thermal regulation achieved via fluid flow within network of embedded vesicles notably desirable slender synthetic material systems. This far-reaching study—availing theory, numerics, experiments—reveals counter-intuitive yet fundamental property vascular-based fluid-flow-engendered regulation. For such thin...