Jayaraman Research Group Paper
Soft Matter Journal selected a recent paper by the Jayaraman Research Group for cover art for Volume 13, Number 16 issued on April 28, 2017, Pages 2895-3062 authored by:
Professor Arthi Jayaraman
The Jayaraman Research Group is in the Center for Molecular & Engineering Thermodynamics of the Department of Chemical & Biomolecular Engineering. Jayaraman Group research focuses on the Theory and Simulations of Polymers and Biomaterials. Recent projects include: Polymer Grafted Nanoparticles Based Polymer Nanocomposites, Conjugated Polymer Materials for Organic Electronics, and Nucleic Acids and Peptide based Biomaterials.
Shear thickening fluid has many applications, including in needlestick-resistant surgical gloves
UD professor featured in American Chemical Society video at SXSW
The hipsters, thought leaders and innovators attending the South by Southwest (SXSW) Festival in Austin, Texas, this week are being introduced to some University of Delaware innovation that’s designed to help people both here on the ground and rocketing off into space. In a video being premiered by the American Chemical Society at SXSW, UD professor Norman Wagner and his interdisciplinary team’s work with shear thickening fluids is showcased — in applications ranging from bullet-proof vests, to needlestick-resistant surgical gloves, concussion-resistant helmets, next-generation prosthetics and even spacesuits. As Wagner explains, shear thickening fluids are “field-responsive” materials meaning that the harder you push on them, the harder they push back. His team’s work to harness this unique capability and provide protection where it currently doesn’t exist — to first responders to doctors to astronauts — is highlighted in one of three short-form documentaries produced by the American Chemical Society. The series illustrates the importance of chemistry in innovation and the cross-collaboration and interdisciplinary nature of today’s scientific endeavors.
In addition to Wagner, who is the Unidel Robert L. Pigford Chaired Professor of Chemical and Biomolecular Engineering at UD, and co-founder of the startup company STF Technologies, the video includes Richard Dombrowski, co-founder of STF Technologies, and research assistant Eric Hobbs, who both received their bachelor’s degrees in chemical engineering from UD, Jehnae Linkins, doctoral student in biomechanics and movement science, and postdoctoral researcher Dr. Maria Katzarova. Eric Wetzel, research scientist and a key partner at the Army Research Laboratory, and John Horne, president of Independence Prosthetics-Orthotics, also are included.
The American Chemical Society, which is participating in the expo hall at SXSW for the first time this year, has more than 157,000 members around the globe. The videos and other information are being presented on its new community engagement platform, the ACS Xchange, which is open to the public. Watch the UD Team’s Video
University of Delaware/NASA Johnson Space Center, Human Exploration & Operations and Space Technology Mission Directorates
As NASA propels science, technology and exploration forward, the need for spacesuits composed of lightweight, long-lived and flexible materials becomes increasingly urgent. In space, micrometeorites and orbital debris (MMOD) can compromise the air barrier of a space suit, causing pinhole punctures that are difficult to identify and repair. Our work focuses on developing healing materials capable of regenerating functionality after damage. In our approach, we are synthesizing fundamentally new, self-healing polymers in which a dynamic bond is built into the network architecture to enable a lightactivated secondary polymerization, increasing the modulus by two orders of magnitude and strengthening the network by over 100%. This work has been recently published in Advanced Materials (2015, 27, 8007–8010). We demonstrated that the material can be completely severed and then remended with increased material strength and no visible scarring. Moreover, our approach confines healing and strengthening to the damaged area; thus, an EVA suit could maintain flexibility in unaffected areas. By developing healing polymer networks, the safety and service lifetime of the material are enhanced. This material was selected by NASA to be tested on the exterior of the International Space Station in 2017 to test its response the extreme environment of outer space. See article…
Stimuli is a summary collection of college and university basic research and technology development reports impacting NASA’s earth science, aviation, and human and robotic deep space exploration programs. This document addresses research which is relevant to NASA’s mission, and currently administered by the agency’s Experimental Program to Stimulate Competitive Research.
Colin D. Cwalina, Charles M. McCutcheon, Richard D. Dombrowski, Norman J. Wagner
Engineering Enhanced Cut and Puncture Resistance into the Thermal Micrometeoroid Garment (TMG) using Shear Thickening Fluid (STF) – Armor™ Absorber Layers
The low-earth orbit environment contains small micrometeoroid and orbital debris (MMOD) particles traveling at characteristic velocities of several kilometers per second. In addition to being a direct threat to astronauts and spacecraft, upon impact with the exterior surface of a space vehicle, these highly energetic MMOD particles can create cut and puncture hazards for astronauts performing extra-vehicular activities (EVA). In this work, we demonstrate that replacing the standard neoprene-coated nylon absorber layers with woven aramid textiles intercalated with colloidal shear thickening fluids, i.e., STF-Armor™, can provide a meaningful enhancement to the cut and puncture resistance of the thermal micrometeoroid garment (TMG). Quasi-static puncture testing is performed using hypodermic needles of varying gauge to simulate the cutting and puncture hazards at deformation rates characteristic of human motion. At equal areal densities, we find that a TMG lay-up containing STF-Armor™ greatly improves puncture protection with a reduction in weight and comparable flexibility.
The primary concern for spacecraft shielding engineers is mitigating the risks posed by natural micrometeoroids originating from comets and asteroids throughout the solar system  and . Over the decades, the increasing number of vehicles and satellites launched into low-earth orbit (LEO) has broadened the focus of design engineers to manmade orbital debris threats  and . These orbital debris particles, largely aluminum-based compounds broken off from LEO vehicles, typically travel at velocities of 1–15 km/s in LEO . While generally on the order of a millimeter or less in size, these micrometeoroid and orbital debris particles (MMOD), are sufficiently energetic to be destructive upon impact. Of particular concern to manned missions is the threat posed by MMOD to astronauts as they perform extra-vehicular activities (EVA). To combat this threat, the current EVA suit consists of an assemblage of textile layers, known as the thermal micrometeoroid garment (TMG), which protects the exterior of the pressurized air bladder as shown in Fig. 1. The design of the TMG primarily seeks to prevent MMOD particles from reaching and puncturing the air bladder upon a direct impact . Read More…
Eric Furst is leading one of five projects recently selected to conduct fluid dynamics investigations in the International Space Station’s U.S. National Laboratory
NSF grant to support research on colloidal materials
The University of Delaware’s Eric Furst is leading one of five projects recently selected to conduct fluid dynamics investigations in the International Space Station’s U.S. National Laboratory. The program is jointly administered by the Center for the Advancement of Science in Space (CASIS) and the National Science Foundation (NSF). NSF will award $1.5 million total in funding for the selected projects to advance fundamental science and engineering knowledge through microgravity inquiry. Furst’s project, “Kinetics of Nanoparticle Self-Assembly in Directing Fields,” will use facilities onboard the space station (ISS) to study the assembly of ellipsoidal magnetic particles in the presence of a controlled magnetic field. A professor in UD’s Department of Chemical and Biomolecular Engineering, Furst is particularly interested in colloidal materials — mixtures in which small particles called colloids are uniformly distributed throughout another substance. These materials range from common household items like mayonnaise, jelly and paint to high-tech applications in medicine, photovoltaics and communications. “The number of functional materials manufactured by assembly of colloidal particles is growing,” says Furst. “With this work, we will be controlling assembly by applying external fields that affect the motion of the particles and their organization.” “Functional materials are fascinating because their mission is to perform in a certain way while basically remaining invisible,” he says. “The cool part for me as a scientist and engineer is revealing that magic to people, but the science behind it can be hard to explain.”
Furst says that some of the simplest “smart materials” are those that flow on demand. “These materials have what’s known as yield stress,” he says. “It’s what keeps toothpaste on our toothbrushes and ketchup on our fries.” “Yield stress is a commonly engineered property in colloidal systems,” he adds. “We’re seeking to use more complex colloidal building blocks to engineer more sophisticated properties, while also enabling new routes to manufacturing those materials by self-assembly.” The colloidal materials examined in this project could serve as building blocks for phononic bandgap materials that control the propagation of sound and heat, ultra-low thermal conductivity coatings, and photonic crystals with rich structural color. In announcing the awards…Read full article