Functional Coatings on High‐Performance Polymer Fibers for Smart Sensing

Abstract

Above a critical temperature, high‐performance fibers may lose their mechanical properties resulting in catastrophic events of damage when, e.g., used as load‐carrying ropes. Here, a method to functionalize polymer fibers with thermochromic optical coatings that enable signaling of damaging thermal history is introduced. These smart coatings are comprised of an index‐tunable anti‐reflection coating based on chalcogenide phase change materials (PCM). It is demonstrated that the insulator−metal phase transition of these materials can be aligned with the critical deterioration temperature of both polyethylene terephthalate (PET) monofilaments and liquid‐crystal polyester (LCP) yarns by composition tuning. The carefully designed optical system amplifies the change in optical properties of its constituents upon phase change. The thermal and mechanical degradation of these fibers can thus be monitored and displayed by eye.

Nanoporous Metallic Network as a Large-Scale 3D Source of Second Harmonic Light

“…which is mediated by plasmons excitation. [4,15] Concentration of the EM energy at sharp nanometer size tips form thereby hot-spots of peak field intensities. These intense EM peaks function as local nonlinear sources for SHG.…”

“…[1,2] If large enough in size, the network becomes robust so that a local damage does not lead to a system failure. [3,4] Such robust disordered networks are of great importance in photonic devices, because they may respond in a cooperative manner to the applied electromagnetic (EM) field. In nature, corals are an example for such a robust disordered system, where light is diffusively scattered enabling symbiotic algae to capture a larger fraction of photons and optimize subaquatic photosynthetic energy production.…”

“…Moreover, their surface curvature and texture changes at the submicron scale, and therefore the EM field lines either converge or diverge, leading to refraction-index modulation at the submicron scale. [4,15] Typically, in such metallic networks there are regions with very high electron density, which thus exhibit strong local fields. These regions lead to excitation of localized plasmonic modes, and are referred as 'hot-spots'.…”

Durability Study of Thermal Transfer Printed Textile Electrodes for Wearable Electronic Applications

“…To realize the fabrication of textile-based electronic devices, the most fundamental element is the conductive electrodes, which are required for interconnection to transfer power and data . The methods for preparation of conductive textile-based electrodes can be categorized into two types: One method is to manufacture conductive fibers or yarns by spinning the conductive solution , or by coating fibers with conductive coatings (dip coating or deposition) ,, and then weave them into different shapes by a weaving machine. This method retains the original breathable properties of the woven fabrics but is limited by the poor compatibility between the conductive fiber and the traditional fiber manufacturing methods and instruments. , For example, a commercial conductive yarn, Shieldex (117/17 × 2 HCB TPU), is coated with silver on the surface of nylon 6.6 yarn and encapsulated with TPU coating.…”

Preparation and Characterization of Flexible Smart Glycol/Polyvinylpyrrolidone/Nano-Al2O3 Phase Change Fibers

“…Flexible smart fibers have broad application prospects in the field of smart thermal textiles. − Smart thermal textiles that act as a first protective barrier to the equipment are becoming increasingly important. Smart thermal textiles with obvious advantages over traditional thermal textiles have attracted considerable attention, which can absorb and release latent heat to regulate the surrounding temperature .…”