I-FMD's Material and Devices
Thursdays at 12 pm
To view recordings, click on the title. You will need to log in with your Lehigh University credentials.
Thursday, June 4
Viral Adhesion and Invasion: What We Learned from Ebola and COVID-19
Frank Zhang, Bioengineering/Mechanical Engineering and Mechanics
Throughout recent human history, viral epidemics or pandemics are often devastating, unpredictable, and occur with increasing frequency. This is likely due to the expansion of the human population, increased travel and trade, escalation in livestock production, and interference with wildlife habitats. For example, bats, a reservoir host of a number of deadly human viruses such as Rabies, Nipah, Marburg, Ebola, and SARS coronaviruses, can pass viruses through intermediate host species that have close contact with humans. In order to infect humans, these viruses will need to attach to the host cell surface, penetrate the host cell membrane, and release their genome into the host cell. In this grand round, I will focus on the attachment and entry processes of two emerging viruses: Ebola and SARS-CoV-2 (i.e., the virus causing COVID-19), and will discuss the latest research findings on their entry pathways and what therapeutic approaches can be derived from a basic understanding of viral adhesion and entry.
X. Frank Zhang, Associate Professor of Bioengineering and Mechanical Engineering & Mechanics, received his PhD in physiology and biophysics from The University of Miami Miller School of Medicine and completed his postdoctoral training at Harvard Medical School. His research focuses on mechanobiology, tissue damage and repair, and virus-host cell interaction.
Thursday, June 11
Dislocations at Soft Interfaces
Anand Jagota, Bioengineering/Chemical and Biomolecular Engineering
The discovery of dislocations as defects in crystalline materials early in the 20th century was one of the most important advances in the science of materials. (We will start by quickly reminding ourselves of what dislocations are: most materials scientists can check their email while I do this!) Dislocations are prime examples of the importance of defects in defining properties of materials. For example, plasticity of metals is entirely governed by the availability of dislocations and their ability to glide through a crystalline solid. Dislocations also allow one to accommodate misorientation between adjacent crystals. A world away are soft materials like elastomers (fancy term for rubbery materials) and gels that are disorganized, amorphous, goo-like stuff with no ordered structure, comprising instead of a floppy network of chain-like molecules with or without a second (also amorphous) liquid phase. No scope for dislocations here, at least not at the atomistic or molecular length scale. However, over the past couple of decades, people have been playing with structuring of soft solid surfaces at the micron scale to enhance properties like adhesion and friction. It turns out that when you bring two such surfaces into mutual contact ……. can’t say any more or I’ll give the game away! You’ll have to attend the talk for the rest. It involves someone called Volterra, micron-sized screw and edge dislocations, their glide as a form of plastic flow, Lothe dislocation cores, and other such stuff.
Anand Jagota is Founding Chair, Professor of Bioengineering, and Professor of Chemical and Biomolecular Engineering at Lehigh University. His training is in Mechanical Engineering, from IIT Delhi for undergraduate studies and Cornell University for graduate work. He worked for nearly 15 years as a materials scientist at the DuPont company and moved in 2004 to Lehigh University. His research interests are in interfacial mechanical properties ranging from biomolecule-nanomaterial hybrids to biomimetic surfaces for enhanced adhesion and friction.
Thursday, June 18
Rare Earth Ions in Semiconductors: From Solid State Lighting to Quantum Communications
Volkmar Dierolf, Physics
Rare earth ions as the active dopant in insulating materials play a significant role in a wide variety of applications that involve the creation of light. Neodymium is the dopant in one of the most commonly used lasers (Nd:YAG), Erbium is at the core of fiber amplifier that are critical for optical communication, Eu is the dopant in phosphors we find in fluorescence lamps and LED light bulbs. Moreover, several schemes have been demonstrated to use these ions for quantum applications. There is however an inherent disadvantage of placing them into an insulator because the excitation of the ion can only be achieved optically with another light source. This limits the ability of integrating with electronics. In our work, we studied the incorporation of ions into wide bandgap semiconductors like gallium nitride which is a prominent material in solid state lighting. We have demonstrated that light emitting diodes (LED) with very high quantum efficiency in the red spectral regime. We further showed that the color of the LED can be tuned by the way the device is electrically excited. These breakthroughs are based on profound understanding of the incorporation of the rare earth ion into the host material and the excitation dynamics that results from that. Finally. I will discuss how such devices could potentially be used in quantum devices that are electrically addressed and read out.
Prof. Dierolf is a Distinguished Professor of Physics and Materials Science and the current Chairperson of the Physics department at Lehigh. He joined Lehigh in 2000 after a post-doc at the University of Paderborn and a PhD from the University of Utah.
In his free time, he is avid skier and has picked up running again last year. He currently trains to qualifier for the Boston marathon. He currently participates in a Virtual Run through PA and hopes to finish the 310 miles by the end of this month.
Thursday, June 25
The Architectured Glass
Himanshu Jain, Materials Science
If there is one material that helped realize modern scientific revolution, it ought to be glass, which made possible Galileo’s telescope and Janssen’s microscope that changed how man saw and understood the universe. Glass revolutionized the building architecture and the way man lived, permitting the light in but not the treacherous weather. Closer to our times, it made internet a reality, and changed today’s cities with skyscrapers – get a glimpse of this transformation - next time compare the largest piece of glass as you enter Linderman Library vs. Fairchild Martindale Library.
The glass is now on its way to change the future technologies as well, by focusing on nanoscale. Unlike the well-defined unique structure of a crystal, the thermodynamically metastable state of glass permits having it in unlimited structural configurations. By using external stimulations, the Lehigh glass team has modified the structure and chemistry locally on nanoscale and created architectures within glass with varying properties. Thus, it introduced new metamaterials for novel applications in micro-photonics (world’s thinnest Fresnel lens), tissue regeneration (first bioactive scaffolds with tailored degradation rate), and integrated optics (world’s first active single crystal 3D waveguide in glass). This Grand Round will tell the story of such architectured glasses pioneered at Lehigh.
Himanshu Jain received his Eng.Sc.D. from Columbia University in Materials Science, and conducted research at Argonne and Brookhaven National Labs before joining Lehigh in 1985. An author of 11 patents and over 390 research publications, he is the editor/author of 10 books on glass science and technology. Over the past three decades, he focused on introducing new functionality and novel processing of glass through fundamentals, and making glass education available worldwide freely. Lately, he has been advocating for use-inspired research, and leading the development of a new graduate education model: Partnership with Researchers in Industry for Doctoral Education (PRIDE).
An interesting fact: Himanshu Jain lacks basic education – he never attended elementary school.
For more information, please contact Nikki Rump.
*Grand Rounds is a term borrowed from the medical education community to share the latest, unique advancements across all specialties. The lectures will be at the “Scientific American” level and will be suitable for all STEM audience.
*All Graduate students and post docs who join the call will be entered into a raffle for $100 gift card!
*Lectures are open to the public and will be recorded.