In this study, we explore the innovative application of biological principles of scattering foams and structural colouration of white materials to manipulate the transmission properties of thermal infrared (IR) radiation, particularly within the 8-14 μm wavelength range in polyolefin materials. Inspired by the complex skin of organisms such as chameleons, which can dynamically change colour through structural alterations, as well as more mundane technologies such as Buddha Boards and magic water colouring books, we are developing methods to control thermal IR transmission using common thermoplastic materials that are semi-transparent to thermal IR radiation. Polyethylene and polypropylene, known for their versatility and cost-effectiveness, can be engineered into microstructured sheets with feature sizes spanning from 5 to 100 μm.
View Article and Find Full Text PDFWe present in this work new methodologies to produce, refine, and interconnect room-temperature liquid-metal-core thermoplastic elastomer wires that have extreme extendibility (>500%), low production time and cost at scale, and may be integrated into commonly used electrical prototyping connectors like a Japan Solderless Terminal (JST) or Dupont connectors. Rather than focus on the development of a specific device, the aim of this work is to demonstrate strategies and processes necessary to achieve scalable production of liquid-metal-enabled electronics and address several key challenges that have been present in liquid metal systems, including leak-free operation, minimal gallium corrosion of other electrode materials, low liquid metal consumption, and high production rates. The ultimate goal is to create liquid-metal-enabled rapid prototyping technologies, similar to what can be achieved with Arduino projects, where modification and switching of components can be performed in seconds, which enables faster iterations of designs.
View Article and Find Full Text PDFThermophysiological comfort is known to play a primary role in maintaining thermal balance, which corresponds to a person's satisfaction with their immediate thermal environment. Among the existing test methods, sweating torsos are one of the best tools to provide a combined measurement of heat and moisture transfer using non-isothermal conditions. This study presents a preliminary numerical model of a single sector sweating torso to predict the thermophysiological comfort properties of fabric systems.
View Article and Find Full Text PDFSensors (Basel)
September 2021
A major challenge with current wearable electronics and e-textiles, including sensors, is power supply. As an alternative to batteries, energy can be harvested from various sources using garments or other textile products as a substrate. Four different energy-harvesting mechanisms relevant to smart textiles are described in this review.
View Article and Find Full Text PDFProtective textiles used for military applications must fulfill a variety of functional requirements, including durability, resistance to environmental conditions and ballistic threats, all while being comfortable and lightweight. In addition, these textiles must provide camouflage and concealment under various environmental conditions and, thus, a range of wavelengths on the electromagnetic spectrum. Similar requirements may exist for other applications, for instance hunting.
View Article and Find Full Text PDFInt J Occup Saf Ergon
September 2010
In several industrial environments, mechanical risks are often combined with various contaminants such as oils and greases, which may reduce the performance of protective gloves against mechanical hazards. However, glove properties are characterized on new and clean specimens, and little is known about their residual resistance once contaminated and over time. In this study, a series of protective gloves used in metalworking companies and garages were exposed to relevant oils and greases.
View Article and Find Full Text PDFInt J Occup Saf Ergon
February 2010
The field of personal protective equipment (PPE) has led to several high technology innovations. Indeed, improved protection against the various possible encountered risks is looked for, in particular at the workplace. This has generated the development of new materials and new manufacturing technologies, as well as the introduction of new applications for existing ones.
View Article and Find Full Text PDFTwo mechanical methods have been developed for the characterization of the flexibility of protective gloves, a key factor affecting their degree of usefulness for workers. The principle of the first method is similar to the ASTM D 4032 standard relative to fabric stiffness and simulates the deformations encountered by gloves that are not tight fitted to the hand. The second method characterizes the flexibility of gloves that are worn tight fitted.
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