Future of additive manufacturing: Overview of 4D and 3D printed smart and advanced materials and their applications

© 2020 Elsevier B.V. 4D printing is an emerging field in additive manufacturing of time responsive programmable materials. The combination of 3D printing technologies with materials that can transform and possess shape memory and self-healing capabilities means the potential to manufacture dynamic structures readily for a myriad of applications. The benefits of using multifunctional materials in 4D printing create opportunities for solutions in demanding environments including outer space, and extreme weather conditions where human intervention is not possible. The current progress of 4D printable smart materials and their stimuli-responsive capabilities are overviewed in this paper, including the discussion of shape-memory materials, metamaterials, and self-healing materials and their responses to thermal, pH, moisture, light, magnetic and electrical exposures. Potential applications of such systems have been explored to include advancements in health monitoring, electrical devices, deployable structures, soft robotics and tuneable metamaterials

Designing Polymer Hydrogels for Extrusion-Based Additive Manufacturing

Thesis (Ph.D.)--University of Washington, 2021Additive manufacturing (AM) technologies are expanding the boundaries of materials science and providing an exciting forum for interdisciplinary research. The ability to fabricate arbitrarily complex objects has made AM technologies indispensable in personalized healthcare, soft electronics, and renewable energy. At the intersection of AM technologies and materials chemistry are stimuli-responsive polymers, which change their chemical and physical properties in response to specific environmental cues. Stimuli-responsive polymer hydrogels, in particular, are seeing significant interest in extrusion-based AM for the fabrication of bespoke medical implants and tissue engineering. The responsiveness of these “smart” hydrogels makes them suitable for AM and provides functionality to the additively manufactured objects. The type of stimulus response, mechanical properties, and functionality of these hydrogels can be regulated through chemical transformations or incorporation of additives. This dissertation describes two fundamentally different approaches to formulating polymer hydrogels for extrusion-based AM. Chapter 1 provides a thorough introduction to AM and stimuli-responsive hydrogels, with emphasis on hydrogels that respond to changes in temperature and shear pressure. Chapter 2 and Chapter 3 describe chemical transformations to the end groups of synthetic block copolymers to afford changes in hydrogel temperature response, mechanical characteristics, and morphology. By contrast, Chapter 4 reports the collaborative development of a 3D-printable bioink based on cardiac decellularized extracellular matrix (cdECM). While Chapter 2 and Chapter 3 deal with molecular-level changes to wholly synthetic polymer systems, Chapter 4 deals with biopolymers derived from porcine cardiac cells that are combined with synthetic additives. The two approaches offer contrasting strategies for the design of polymer hydrogels for AM

Replication Data for: Political Considerations in Nonpolitical Decisions: A Conjoint Analysis of Roommate Choice

Replication Data for: Political Considerations in Nonpolitical Decisions: A Conjoint Analysis of Roommate Choic

Erin Shafranek - Master of Music - Masters Recital

Sorge l'irato nembo, from Orlando furioso / Antonio Vivaldi (1678-1741)--Le colibri; Le temps des lilas; Le Charme, Op. 2, No. 2 / Ernest Amédée Chausson (1855-1899)--Funf Gesange, Op. 72 : Alte Liebe; Sommerfaden; O kühler Wald; Verzagen; Unüberwindlich / Johannes Brahms (1833-1897)--INTERMISSION--Love's Waning Seasons : Autumn; A Winter Night; I So Liked Spring; Shall I Compare Thee To A Summer's Day? / Zane Randall Stroope (b. 1953)--Malinconia, ninfa gentile; Ma rendi pur contento; Per pietà bell'idol mio / Vincenzo Bellini (1801-1835)--Paper Wings : Bedtime Story; Paper Wings; Mitten Smitten; A Route to the Sky / Jake Heggie (b. 1961)Music, Moores School o

Replication Data for: The Intersection of Racial and Partisan Discrimination: Evidence from a Correspondence Study of Four-Year Colleges

This is replication data for Evidence from a Correspondence Study of Four-Year Colleges. It is not the complete data set since that includes data that would allow one to identify individual respondents (i.e., schools). We are happy to send the full data set upon request and an agreement to keep respondent identification confidential

Replication Data for: Pigeonholing Partisans: Stereotypes of Party Supporters and Partisan Polarization

These are the replication files for Pigeonholing Partisans. They include the R scripts to conduct the analyses in the paper and online appendix and the datasets (as .dta files)

Sticky Ends in a Self-Assembling ABA Triblock Copolymer: The Role of Ureas in Stimuli-Responsive Hydrogels

Directing polymer self-assembly through noncovalent interactions is a powerful way to control the structure and function of nanoengineered materials. Dynamic hydrogen bonds are particularly useful for materials with structures that change over time or in response to specific stimuli. In the present work, we use the supramolecular association of urea moieties to manipulate the morphology, thermal response, and mechanical properties of soft polymeric hydrogels. Urea-terminated poly(isopropyl glycidyl ether)-b-poly(ethylene oxide)-b-poly(isopropyl glycidyl ether) ABA triblock copolymers were synthesized using controlled, anionic ring-opening polymerization and subsequent chain-end functionalization. Triblock copolymers with hydroxy end-groups were incapable of hydrogelation, while polymers terminated with meta-bis-urea motifs formed robust gels at room temperature. Rheometric analysis of the bulk gels, variable-temperature infrared spectroscopy (VT-IR), differential scanning calorimetry (DSC), and small-angle X-ray scattering (SAXS) confirmed the formation of structured hydrogels via association of the meta-bis-urea end-groups. Monourea end-groups did not result in the same regular structure as the meta-bis-urea. In future, the reported hydrogels could be useful for elastomeric, shape-morphing 3D-printed constructs, or as biomimetic scaffolds with precisely tailored porosity and mechanical properties