EVA Suit MMOD Protection Using STF-ArmorTm, Self-Healing Polymers

NASA EPSCoR Stimuli Highlight 2016-2017: Melisssa Gordon and Prof. Norman Wagner of the University of Delaware, and Willie Williams, NASA, Johnson Space Center

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.

Editor’s Highlights for Composites Science and Technology

Colin D. Cwalina, Charles M. McCutcheon, Richard D. Dombrowski, Norman J. Wagner

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 [1] and [2]. 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 [3] and [4]. These orbital debris particles, largely aluminum-based compounds broken off from LEO vehicles, typically travel at velocities of 1–15 km/s in LEO [2]. 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 [5]. Read More…

Self-Assembly in Space

UD'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

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

ACNS Achievement Awards

ACNS Meeting

2016 American Conference on Neutron Scattering Queen Mary in Long Beach, California

Four Awards Were Presented to UD and Former UD Students and Faculty

Four awards were presented to UD and former UD students and faculty at the 2016 American Conference on Neutron Scattering on the Queen Mary in Long Beach CA in July. [From left to right in picture] Prof. Norman Wagner received the Neutron Scattering Society of America’s Service Award for his work on the executive committee and long-standing efforts to raise funding for students, post docs, and young scientists to attend the meeting. Ph.D. student, Michelle Calabrese of the Department of Chemical and Biomolecular Engineering, won one of four student poster prizes out of a field of over 80 scientific posters for her work on understanding the effects of branching on the flow of self-assembled surfactants. Former PhD student, Dr. P. Douglas Godfrin, won the Best Dissertation Award, while Dr. Yun Liu, UD Research Associate Professor and NIST Beamline Scientist won the Science Prize of the ACNS. Dr. Godfrin received his PhD in 2015 for his work on understanding the properties and stability of monoclonal antibodies and protein solutions under the advisement of Prof. Wagner and Dr. Liu. The ACNS is held once every two years and is the premier North American scientific venue for presenting and discussing scientific advances afforded by neutron scattering methods.

Excellence in Graduate Polymer Research Award

Melissa Gordon, University of Delaware Doctoral candidate in Chemical Engineering

Melissa Gordon, University of Delaware Doctoral candidate in Chemical Engineering

Chemical Engineering Honors from the American Chemical Society

The 12th Excellence in Graduate Polymer Research Symposium took place at the ACS national meeting, held in San Diego from March 13-17. The symposium recognizes outstanding graduate students in polymer science and engineering, fosters networking and exposure, and helps to develop the careers of future leaders in the field. Gordon delivered an oral presentation on her research, which focuses on developing novel stimuli-triggered polymer networks for self-healing applications. “Stimuli-triggered processes found in nature, such as the contraction of our eyes in response to bright light or healing after a cut, motivate the design of ‘smart’ materials that can respond to environmental cues, such as light, temperature or pH,” Gordon says. Gordon, who has accepted a faculty position at Lafayette College beginning in January 2017, is co-advised by Norman Wagner, the Unidel Robert L. Pigford Chaired Professor of Chemical and Biomolecular Engineering, and Christopher Kloxin, assistant professor. Read more…