Solvay Seminar Series

Note: The remainder of the Spring seminars have been cancelled with the hope of rescheduling for next year. This includes Enrique Gomez (March 18), Chad Ulven (April 15), and Cole DeForest (April 22). 

Spring 2020 Solvay Seminar Series

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Prof. Brett Compton

University of Tennessee, Knoxville

Assistant Professor, Mechanical Engineering

"Understanding Print Stability in Material Extrusion Additive Manufacturing of Thermoset Composites"

Date

Wednesday, February 5

Time

11:15 AM - 12:15 PM

Location

Kelly Hall 310

Brett is currently an assistant professor of mechanical engineering at the University of Tennessee, Knoxville. Brett moved to UTK from Oak Ridge National Laboratory where he was a staff scientist in additive manufacturing (AM) at the Manufacturing Demonstration Facility (MDF). The MDF is the Department of Energy’s flagship additive manufacturing center, and his research there included thermo-mechanical modeling of large-scale polymer composite AM and in situ thermal imaging of metal powder bed systems. Prior to moving to Tennessee, Brett was a Postdoctoral Research Fellow in the Lewis Group in the School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering at Harvard University, where he developed materials and techniques to 3D print short fiber-reinforced thermoset polymer resins to enable bio-inspired, lightweight polymer composites with controlled fiber orientation. Brett received his Ph.D. in Materials from the University of California, Santa Barbara, and his B.S. in Mechanical Engineering from the University of Kentucky. Research areas include additive manufacturing of polymer and ceramic composites, understanding the effects of processing parameters on fiber orientation and material anisotropy, novel methods to control fiber orientation in printed composites, and understanding the effects of hierarchy multi-scale composite structures.

Over the last several years, rapid progress has been made in 3D printing of thermoset polymer resins. Such materials offer desirable thermal and chemical stability, attractive strength and stiffness, and excellent compatibility with many existing high performance fibers. Material extrusion additive manufacturing (AM) is an ideal technology to print thermoset-based composites because fibers align during extrusion through the deposition nozzle, thereby enabling the engineer to design fiber orientation into the printed component. Current efforts to scale thermoset AM up to large-scale have shown promise, but have also highlighted issues with print stability. To-date, very little research has focused on understanding how rheological properties of the feedstock dictate the mechanical stability of printed objects. This talk will describe our first efforts in this area by printing tall, thin walls to characterize buckling and yielding due to self-weight.

The talk will begin with an overview of thermoset material extrusion AM, including a brief history and the current state of the art in small and large-scale printing. The talk will then describe simple thin-walled test geometry and experimental setup that enable quantitative assessment and monitoring of geometric stability during the printing process using machine vision. Two feed stocks are investigated, each having different rheological properties, and the height at which buckling begins and the height at which full collapse occurs are identified as a function of wall thickness. Complementary rheological characterization shows that collapse of thin printed walls is well predicted by the classical self-weight, elastic buckling model, provided the recovery behavior of the feedstock is accounted for. These tests highlight the importance of understanding recovery in material extrusion AM feedstocks and could lead to the design of better resins and fillers, and could provide guidelines for the selection of successful print parameters for both small and large-scale thermoset AM. The talk will conclude with a brief discussion of next steps and outlook on the future of material extrusion AM of thermoset materials. 

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Prof. Qingguo Xu

Virginia Commonwealth University

Blick Scholar Assistant Professor of Pharmaceutics, Ophthalmology, Massey Cancer Center, and the Center for Pharmaceutical Engineering

"Long-Lasting Polymeric Nanotherapeutics for the Treatment of Eye Diseases"

Date

Wednesday, February 12

Time

11:15 AM - 12:15 PM

Location

Kelly Hall 310

Dr. Qingguo Xu is a Blick Scholar Assistant Professor of Pharmaceutics, Ophthalmology, Massey Cancer Center, and the Center for Pharmaceutical Engineering at the Virginia Commonwealth University since 2017. He received B.E. and M.E. in Polymer Materials and Engineering from Tianjin University, and D.Phil. in Materials Science from University of Oxford at 2009. Dr. Xu was a postdoc fellow in the Wilmer Eye Institute at Johns Hopkins University School of Medicine, and 3 years later he became a Research Faculty member. He has experience in materials science, drug delivery, nanotechnology, and physiochemical characterization of mucosal and tissue barriers to drug delivery systems. A significant portion of his current work has involved the design and development of new methods for safe, effective drug delivery to treat various eye diseases, lung infection, and opioid use disorder.  He is the PI and co-PI of a NIH/NEI R01, a NIH/NIDA UG3 and a FDA grant with total funding ~ $5 million within 2 years after joining VCU. Dr. Xu has authored about 30 research papers and 10 patents and patent applications, 3 of which have been licensed to companies for commercialization. These efforts have led to awards and recognitions, including Blick Scholar (2019), Young Investigator of CRS Ocular Delivery (2019), Ralph E. Powe Junior Faculty Award (2018), AAPS-Genentech Innovation in Biotechnology Award (2013), EBAA/Richard Lindstrom Award (2013).

Blindness represent a substantial burden to the healthcare system. However, delivering therapeutics to the eye is a challenge on multiple levels. Rapid clearance of medications in eye drops requires that they be applied frequently, but patient compliance with eye drop regimens is poor (e.g., glaucoma patients only take roughly one-half of their doses correctly). In addition, drug penetration to the back of eye following topical administration is limited due to multiple ocular barriers. On the other hand, the blood-retinal barrier limits the delivery of drugs into the eye following systemic administration. In this talk, I will present a long-lasting polymeric nanotherapeutics engineered to enhance ocular therapeutic activity through prolonging drug half-life, releasing drugs in a controlled fashion, and eliminating toxic side effects for improved treatment of eye diseases.

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Prof. Tim White

University of Colorado Boulder

Gallogly Professor of Engineering, Dept. of Chemical and Biological Engineering

"Enabling Functional Outcomes by Programming the Responsivity of Liquid Crystalline Polymer Networks and Elastomers"

Date

Wednesday, February 26

Time

11:15 AM - 12:15 PM

Location

Kelly Hall 310

Timothy J. White received his Ph.D. in Chemical and Biochemical Engineering in 2006 from the University of Iowa. Subsequently he joined the Air Force Research Laboratory where he served as a Senior Research Engineer and Technology Advisor of the Photonic Materials Branch in the Materials and Manufacturing Directorate. In this capacity, Dr. White led a large interdisciplinary team executing basic, applied, and developmental research projects. In July of 2018, Tim joined the faculty at the University of Colorado Boulder as the inaugural Gallogly Professor of Engineering. Tim leads the "Responsive and Programmable Materials" Group, pursuing research generally focused on programming functional responses in organized materials. Prof. White has more than 140 papers in peer-reviewed journals. Dr. White has been honored with the 2019 Soft Matter Lectureship, 2016 Materials Research Society “Outstanding Young Investigator” award, the 2013 SPIE Early Career Achievement award, the 2013 American Chemical Society PMSE Division Award for “Cooperative Research in Applied Polymer Science”, and the 2012 Air Force Early Career Award. Tim is active in the materials research community including leadership activities with the American Chemical Society (POLY), Materials Research Society, and SPIE.  

Liquid crystalline materials are pervasive in our homes, purses, and pockets. It has been long-known that liquid crystallinity in polymers enables exceptional characteristics in high performance applications such as transparent armor or bulletproof vests. This talk will generally focus on a class of liquid crystalline materials:  liquid crystalline elastomers. These materials were predicted by de Gennes to have exceptional promise as artificial muscles, owing to the unique assimilation of anisotropy and elasticity. Subsequent experimental studies have confirmed the salient features of these materials, with respect to other forms of stimuli-responsive soft matter, are large stroke actuation up to 75% as well "soft elasticity" (stretch at minimal stress). 

This presentation will survey our efforts in directing the self-assembly of these materials to realize distinctive functional behavior with implications to soft robotics, flexible electronics, and biology. Most notably, enabled by the chemistries and processing methods developed in my laboratories, we have prepared liquid crystal elastomers with distinctive actuation and mechanical properties realizing nearly 20 J/kg work capacities in homogenous material compositions. Local control of orientation dictates nonuniformity in the elastic properties, which we recently have shown could be a powerful means of ruggedizing flexible electronic devices. Facile preparation of optical films, prepared with the cholesteric phase, capable of concurrent shape and color change will be presented. 

Enrique Gomez wears glasses and a bowtie and smiles.

Prof. Enrique Gomez

Penn State University

Professor, Chemical Engineering

"Pushing the Limits of Electron Microscopy of Polymers"

Date

Wednesday, March 18 (Postponed)

Time

 

Location

 

Enrique D. Gomez received a B.S. in Chemical Engineering from the University of Florida in 2002, received a Ph.D. in Chemical Engineering from the University of California, Berkeley in 2007, and spent a year and a half as a postdoctoral research associate at Princeton University. Dr. Gomez joined the faculty at the Pennsylvania State University in August of 2009, where he is now a Professor of Chemical Engineering and Materials Science and Engineering.

Research activities of Dr. Gomez are focused in understanding how structure at various length scales affects macroscopic properties of soft condensed matter. To this end, the Gomez group pushes the limits of X-ray scattering and electron microscopy to refine descriptions of the microstructure of soft materials. The current emphasis of his research group is on the relationship between microstructure and electrical properties in the active layers of organic thin film transistors and photovoltaics, and in the development of microstructure control to enable sustainable materials.

Enrique has received multiple awards, including a Visiting Scientist Fellowship from the National Center for Electron Microscopy, the Ralph E. Powe Junior Faculty Award by the Oak Ridge Associated Universities, the National Science Foundation CAREER Award, the Rustum and Della Roy Innovation in Materials Research Award, and the Penn State Engineering Alumni Society Outstanding Research Award. 

Imaging of polymers by transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM) remains a challenge due to the low contrast between domains and sensitivity to the electron beam. Recent advances in instrumentation for electron microscopy have aimed to push the resolution limit, leading to remarkable instruments capable of imaging at 0.5 Å. But, when imaging soft materials, the resolution is often limited by the amount of dose the material can handle rather than the instrumental resolution. Despite the strong constraints placed by radiation sensitivity, recent developments in electron microscopes have the potential to advance polymer electron microscopy. For example, monochromatated sources enable spectroscopy and imaging based on the valence electronic structure, electron tomography allows the reconstruction of 3D microstructures, direct electron detectors minimize the required dose for imaging, and differential phase contrast imaging can map heterogeneities in electric fields within films. Key to these efforts is characterization of the mechanism for radiation damage in the TEM, which suggests new strategies to minimize damage, and thereby push the resolution limit down to 3.6 Å. Altogether, the field of polymer electron microscopy is poised to make significant advances in the near future. 

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Prof. Chad Ulven

North Dakota State University

Professor, Mechanical Engineering

"Sustainability and Durability of Natural Fiber Composites"

Date

Wednesday, April 15 (Postponed)

Time

Location

Dr. Ulven received his B.S. degree in Mechanical Engineering from North Dakota State University (2001) and M.S. and Ph.D. degrees in Materials Engineering from the University of Alabama at Birmingham (2003 & 2005). He has been a faculty member in the Mechanical Engineering Department at North Dakota State University since August of 2005. He has been involved in the research of polymer matrix composites (PMCs) for various commercial and defense applications for the past 19 years. He has co-authored 6 book chapters, 70 journal articles, and over 100 conference papers related to PMCs. He has been a co-author of 5 patent applications which have led to 4 patents awarded and 2 spin-out companies (c2renew inc. and c2sensor corp.).    

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Prof. Cole DeForest

University of Washington

Dan Evans Career Development Assistant Professor of Chemical Engineering and Assistant Professor of Bioengineering

"User-Programmable Hydrogel Biomaterials to Probe and Direct 4D Stem Cell Fate"

Date

Wednesday, April 22 (Postponed)

Time

Location

Dr. Cole A. DeForest is the Dan Evans Career Development Assistant Professor in the Department of Chemical Engineering, an Assistant Professor in the Department of Bioengineering, and a core faculty member of the Institute for Stem Cell & Regenerative Medicine at the University of Washington (UW) where he began in 2014.

He received his B.S.E. degree from Princeton University in 2006, majoring in Chemical Engineering and minoring in Material Science Engineering and Bioengineering. He earned his Ph.D. degree under the guidance of Dr. Kristi Anseth from the University of Colorado in Chemical and Biological Engineering with an additional certificate in Molecular Biophysics. His postdoctoral research was performed with Dr. David Tirrell in the Divisions of Chemistry and Chemical Engineering at the California Institute of Technology.

He has authored ~45 peer-reviewed articles, including as the corresponding author for those appearing in Nature Materials, Nature Chemistry, Advanced Materials, and Nature Reviews Materials. Dr. DeForest has received numerous research awards and honors including the Safeway Early Career Award (2018), NSF CAREER Award (2017), AIChE 35-Under-35 Award (2017), ACS PMSE Young Investigator Award (2017), Jaconette L. Tietze Young Scientist Award (2015), Biomedical Engineering Society Student Fellow Award (2013), DSM Polymer Technology Award (2011), ACS Excellence in Graduate Polymer Research Award (2010), MRS Graduate Student Research Gold Award (2009), Society for Biomaterials Outstanding Achievement Award (2009), Princeton University Material Science Student of the Year (2006), Princeton University Most Approachable Resident Adviser (2005), and Boulder High School Valedictorian (2002).

Notably, he has also been recognized for excellence in teaching and was awarded the UW Presidential Distinguished Teaching Award (2016), given annually to a single Assistant Professor across all of the UW. His research has been supported through fellowships and grants from the National Science Foundation, the National Institutes of Health, and the US Department of Education.

The extracellular matrix directs stem cell function through a complex choreography of biomacromolecular interactions in a tissue-dependent manner. Far from static, this hierarchical milieu of biochemical and biophysical cues presented within the native cellular niche is both spatially complex and ever changing. As these pericellular reconfigurations are vital for tissue morphogenesis, disease regulation, and healing, in vitro culture platforms that recapitulate such dynamic environmental phenomena would be invaluable for fundamental studies in stem cell biology, as well as in the eventual engineering of functional human tissue. In this talk, I will discuss some of our group’s recent success in reversibly modifying both the chemical and physical aspects of synthetic cell culture platforms with user-defined spatiotemporal control. Results will highlight our ability to modulate intricate cellular behavior including stem cell differentiation, protein secretion, and cell-cell interactions in 4D.



Spring 2020 Solvay Seminar Series At A Glance

Speaker, Institution

Seminar Title

Date

Prof. Brett Compton
University of
Tennessee, Knoxville

"Understanding Print Stability in Material
Extrusion Additive Manufacturing of
Thermoset Composites"

February 5, 2020
11:15 AM – 12:15 PM
Kelly Hall 310

Prof. Qingguo Xu
Virginia Commonwealth University
"Long-Lasting Polymeric Nanotherapeutics for the Treatment of Eye Diseases"

February 12, 2020
11:15 AM – 12:15 PM
Kelly Hall 310

Prof. Tim White
University of Colorado Boulder

"Enabling Functional Outcomes by Programming the Responsivity of
Liquid Crystalline Polymer Networks and Elastomers"

February 26, 2020
11:15 AM – 12:15 PM
Kelly Hall 310

Prof. Enrique Gomez
Penn State University

"Pushing the Limits of Electron Microscopy of Polymers"

March 18, 2020
(Postponed)

Prof. Chad Ulven
North Dakota State University

"Sustainability and Durability of Natural Fiber Composites"

April 15, 2020
(Postponed)

Prof. Cole DeForest
University of Washington

"User-Programmable Hydrogel Biomaterials to
Probe and Direct 4D Stem Cell Fate"
April 22, 2020 (Postponed)