Preparation and application practice of temperature self‐regulating flexible polymer electric heaters

Author(s):  
Imran Ali ◽  
Alexandr Shchegolkov ◽  
Aleksei Shchegolkov ◽  
Natalya Zemtsova ◽  
Vladimir Bogoslovskiy ◽  
...  
Keyword(s):  
1993 ◽  
Vol 58 (10) ◽  
pp. 2290-2304 ◽  
Author(s):  
Zuzana Limpouchová ◽  
Karel Procházka

Monte Carlo simulations of chain conformations in a restricted spherical volume at relatively high densities of segments were performed for various numbers of chains, N, and chain lengths (number of segments), L, on a tetrahedral lattice. All chains are randomly end-tethered to the surface of the sphere. A relatively uniform surface density of the tethered ends is guaranteed in our simulations. A simultaneous self-avoiding walk of all chains creates starting conformations for a subsequent equilibration. A modified algorithm similar to that of Siepmann and Frenkel is used for the equilibration of the chain conformations. In this paper, only a geometrical excluded volume effect of segments is considered. Various structural and conformational characteristics, e.g. segment densities gS(r), free end densities gF(r) as functions of the position in the sphere (a distance from the center), distributions of the tethered-to-free end distances, ρTF(rTF), etc. are calculated and their physical meaning is discussed. The model is suitable for studies of chain conformations is swollen cores of multimolecular block copolymer micelles and for interpretation of non-radiative excitation energy migration in polymeric micellar systems.


Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 1011
Author(s):  
Dimitre Z. Dimitrov ◽  
Zih Fan Chen ◽  
Vera Marinova ◽  
Dimitrina Petrova ◽  
Chih Yao Ho ◽  
...  

In this work, highly conductive Al-doped ZnO (AZO) films are deposited on transparent and flexible muscovite mica substrates by using the atomic layer deposition (ALD) technique. AZO-mica structures possess high optical transmittance at visible and near-infrared spectral range and retain low electric resistivity, even after continuous bending of up to 800 cycles. Structure performances after bending tests have been supported by atomic force microscopy (AFM) analysis. Based on performed optical and electrical characterizations AZO films on mica are implemented as transparent conductive electrodes in flexible polymer dispersed liquid crystal (PDLC) devices. The measured electro-optical characteristics and response time of the proposed devices reveal the higher potential of AZO-mica for future ITO-free flexible optoelectronic applications.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2605
Author(s):  
Ashley Novais ◽  
Carlos Calaza ◽  
José Fernandes ◽  
Helder Fonseca ◽  
Patricia Monteiro ◽  
...  

Multisite neural probes are a fundamental tool to study brain function. Hybrid silicon/polymer neural probes combine rigid silicon and flexible polymer parts into one single device and allow, for example, the precise integration of complex probe geometries, such as multishank designs, with flexible biocompatible cabling. Despite these advantages and benefiting from highly reproducible fabrication methods on both silicon and polymer substrates, they have not been widely available. This paper presents the development, fabrication, characterization, and in vivo electrophysiological assessment of a hybrid multisite multishank silicon probe with a monolithically integrated polyimide flexible interconnect cable. The fabrication process was optimized at wafer level, and several neural probes with 64 gold electrode sites equally distributed along 8 shanks with an integrated 8 µm thick highly flexible polyimide interconnect cable were produced. The monolithic integration of the polyimide cable in the same fabrication process removed the necessity of the postfabrication bonding of the cable to the probe. This is the highest electrode site density and thinnest flexible cable ever reported for a hybrid silicon/polymer probe. Additionally, to avoid the time-consuming bonding of the probe to definitive packaging, the flexible cable was designed to terminate in a connector pad that can mate with commercial zero-insertion force (ZIF) connectors for electronics interfacing. This allows great experimental flexibility because interchangeable packaging can be used according to experimental demands. High-density distributed in vivo electrophysiological recordings were obtained from the hybrid neural probes with low intrinsic noise and high signal-to-noise ratio (SNR).


2021 ◽  
Vol 33 (34) ◽  
pp. 2170264
Author(s):  
Boya Zhang ◽  
Jingjing Liu ◽  
Ming Ren ◽  
Chao Wu ◽  
Thomas J. Moran ◽  
...  

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1468
Author(s):  
Luis Nagua ◽  
Carlos Relaño ◽  
Concepción A. Monje ◽  
Carlos Balaguer

A soft joint has been designed and modeled to perform as a robotic joint with 2 Degrees of Freedom (DOF) (inclination and orientation). The joint actuation is based on a Cable-Driven Parallel Mechanism (CDPM). To study its performance in more detail, a test platform has been developed using components that can be manufactured in a 3D printer using a flexible polymer. The mathematical model of the kinematics of the soft joint is developed, which includes a blocking mechanism and the morphology workspace. The model is validated using Finite Element Analysis (FEA) (CAD software). Experimental tests are performed to validate the inverse kinematic model and to show the potential use of the prototype in robotic platforms such as manipulators and humanoid robots.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2169
Author(s):  
Agnieszka Tabaczyńska ◽  
Anna Dąbrowska ◽  
Marcin Masłowski ◽  
Anna Strąkowska

Electro-conductive paths that are mechanically resistant and stable during simulated aging cycles are promising, in relation to the non-invasive application in e-textiles in our everyday surroundings. In the paper, an analysis of the influence of electro-conductive filler, as well as ionic liquid on surface resistance is provided. Authors proved that depending on the tested variant, obtained surface resistance may vary from 50 kΩ (when 50 phr of Ag and [bmim][PF6] ionic liquid applied) to 26 GΩ (when 25 phr of Ag and [bmim][PF6] ionic liquid applied). The samples were also evaluated after simulated aging cycles and the stability of electric properties was confirmed. Moreover, it was proved that the addition of ionic liquids reduced the resistance of vulcanizates, while no significant influence of the extrusion process on conductivity was observed.


2021 ◽  
pp. 2101374
Author(s):  
Boya Zhang ◽  
Jingjing Liu ◽  
Ming Ren ◽  
Chao Wu ◽  
Thomas J. Moran ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1225
Author(s):  
Ali Atta ◽  
Mostufa M. Abdelhamied ◽  
Ahmed M. Abdelreheem ◽  
Mohamed R. Berber

In order to potentiate implementations in optical energy applications, flexible polymer composite films comprising methyl cellulose (MC), polyaniline (PANI) and silver nanoparticles (AgNPs) were successfully fabricated through a cast preparation method. The composite structure of the fabricated film was confirmed by X-ray diffraction and infrared spectroscopy, indicating a successful incorporation of AgNPs into the MC/PANI blend. The scanning electron microscope (SEM) images have indicated a homogenous loading and dispersion of AgNPs into the MC/PANI blend. The optical parameters such as band gap (Eg), absorption edge (Ed), number of carbon cluster (N) and Urbach energy (Eu) of pure MC polymer, MC/PANI blend and MC/PANI/Ag films were determined using the UV optical absorbance. The effects of AgNPs and PANI on MC polymer linear optical (LO) and nonlinear optical (NLO) parameters including reflection extinction coefficient, refractive index, dielectric constant, nonlinear refractive index, and nonlinear susceptibility are studied. The results showed a decrease in the band gap of MC/PANI/AgNPs compared to the pure MC film. Meanwhile, the estimated carbon cluster number enhanced with the incorporation of the AgNPs. The inclusion of AgNPs and PANI has enhanced the optical properties of the MC polymer, providing a new composite suitable for energy conversion systems, solar cells, biosensors, and nonlinear optical applications.


2021 ◽  
pp. 009524432110290
Author(s):  
Mukaddes Sevval Cetin ◽  
Ozan Toprakci ◽  
Omer Suat Taskin ◽  
Abdullah Aksu ◽  
Hatice Aylin Karahan Toprakci

This study focuses on the fabrication and characterization of vermiculite-filled flexible polymer composites. Exfoliated vermiculite was incorporated into triblock thermoplastic elastomer copolymer, styrene- b-(ethylene- co-butylene)- b-styrene (SEBS), at various levels from 1 to 15 wt% by a high shear mixer. The composite films were obtained by the combination of solvent casting and compression molding. The morphological, structural, thermal, and mechanical properties and contact angle of the composites were determined. Some micro-morphological differences were observed between the samples and the difference was assumed to be caused by high shear mixing and filler concentration. High shear mixing was found effective in terms of the detachment of vermiculite layers at all concentrations. However, at low filler loading, that behavior was more obvious. At 1 wt% filler concentration, mechanical properties increased that was probably caused by good filler-matrix interaction stemmed from smaller particle size. At higher vermiculite concentrations, fillers found to show agglomerations that led to a decrease in mechanical strength and strain at break. Elastic and secant modulus showed an increasing trend. Contact angle measurements were carried out to determine the oleophilic character of the samples. An increase in the vermiculite content resulted in higher oleophilic character and the lowest contact angle was obtained at 15 wt% VMT loading. In addition to these, thermal stability, thermal dimensional stability and flame retardancy were improved by the incorporation of VMT. 15 wt% vermiculite-filled sample showed the best performance in terms of thermal stability and flame retardancy.


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