keyword
https://read.qxmd.com/read/38475336/poly-ester-imide-s-with-low-linear-coefficients-of-thermal-expansion-and-low-water-uptake-vii-a-strategy-to-achieve-ultra-low-dissipation-factors-at-10-ghz
#21
JOURNAL ARTICLE
Masatoshi Hasegawa, Taro Fukuda, Junichi Ishii
In this study, a series of ester-linked tetracarboxylic dianhydrides (TCDAs) with 2,6-naphthalene-containing longitudinally extended structures consisting of different numbers of aromatic rings ( N Ar = 6-8) was synthesized to obtain novel modified polyimides, poly(ester imide)s (PEsIs). These TCDAs were fully compatible with the conventional manufacturing processes of conventional polyimide (PI) systems. As an example, the PEsI film obtained from the ester-linked TCDA ( N Ar = 8) and an ester-linked diamine achieved unprecedented outstanding dielectric properties without the support of fluorinated monomers, specifically an ultra-low dissipation factor (tan δ ) of 0...
February 28, 2024: Polymers
https://read.qxmd.com/read/38456122/implantation-accuracy-of-novel-polyimide-stereotactic-electroencephalographic-depth-electrodes-a-human-cadaveric-study
#22
JOURNAL ARTICLE
Aura Kullmann, Farida Akberali, Jaime J Van Gompel, Robert A McGovern, W Richard Marsh, Debra Kridner, Camilo A Diaz-Botia, Michael C Park
INTRODUCTION: Stereoelectroencephalography (sEEG) is a minimally invasive procedure that uses depth electrodes stereotactically implanted into brain structures to map the origin and propagation of seizures in epileptic patients. Implantation accuracy of sEEG electrodes plays a critical role in the safety and efficacy of the procedure. This study used human cadaver heads, simulating clinical practice, to evaluate (1) neurosurgeon's ability to implant a new thin-film polyimide sEEG electrode according to the instructions for use (IFU), and (2) implantation accuracy...
2024: Frontiers in medical technology
https://read.qxmd.com/read/38453681/multifunctional-moc-x-hybrid-polyimide-aerogel-with-modified-porous-defect-engineering-for-highly-efficient-electromagnetic-wave-absorption
#23
JOURNAL ARTICLE
Tong Liu, Yanan Zhang, Chong Wang, Yifan Kang, Miao Wang, Fan Wu, Wenhuan Huang
Traditional electromagnetic absorbing materials (EWAMs) are usually single functions and can easily affect their performance in diverse application scenarios. Effective integration of EWAMs into multiple function components is a valuable strategy to achieve maximum absorption and multifunction performance while maintaining their indispensable physical and chemical properties. In this work, the polyoxometalates (POMs) serving as "guests" are embedded within the Co-MOFs to construct 3d/4d-bimetallic based crystalline precursors of dielectric/magnetic synergistic system...
March 7, 2024: Small
https://read.qxmd.com/read/38445353/mechanical-enhancement-and-high-linearity-health-monitoring-of-composite-materials-based-on-cnts-psf-pi-film-sensor-with-ultra-low-swcnts-doping-content
#24
JOURNAL ARTICLE
Xiaoyu Cui, Ying Wang, Shaowei Lu, Yuxuan Wang, Binbin Zhang, Yuxuan Yang, Yunqi Xie, Lu Zhang
A new type of embedded composite material health monitoring nano-sensor is designed to ensure that the unique material advantages of nanofillers can be maximized. The carbon nanotubes (CNTs)/polysulfone (PSF)/polyimide (PI) thin film sensor in this paper is obtained by the self-assembly of a PSF/PI asymmetric porous membrane which is prepared by a phase inversion method through vacuum filtration of SWCNTs. It is a new structure for a practical CNT sensor that can take into account both 'composite health monitoring and damage warning' and 'composite mechanical enhancement'...
March 6, 2024: Nanoscale
https://read.qxmd.com/read/38441047/bifunctional-sulfhydryl-based-polyimides-for-highly-active-cathodes-of-li-s-batteries
#25
JOURNAL ARTICLE
Mengke Li, Han Wang, Gaojie Yan, Zongjie Hu, Yi Feng, Xiaojie Zhang
Sulfhydryl-based polyimides were synthesized by the nucleophilic ring-opening reaction of thiolactone monomers (BPDA-T, ODPA-T, BTDA-T) with polyethylenimine (PEI), and they were coated on carbon nanotubes as host materials (BPTP@CNT, ODTP@CNT, and BTTP@CNT) of the sulfur cathode. BPTP@CNT/S, ODTP@CNT/S, and BTTP@CNT/S as cathode materials not only promote the covalent bonding of sulfur and polysulfide with sulfhydryl-based polyimides but also reduce the shuttle effect of soluble polysulfide in the redox process...
March 5, 2024: ACS Applied Materials & Interfaces
https://read.qxmd.com/read/38440402/mild-selective-photochemical-oxidation-of-an-organic-sulfide-using-oxp-polyimide-porous-polymers-as-singlet-oxygen-generators
#26
JOURNAL ARTICLE
Jan Hynek, Daniel T Payne, Lok Kumar Shrestha, Mandeep K Chahal, Renzhi Ma, Jiang Dong, Katsuhiko Ariga, Yusuke Yamauchi, Jonathan P Hill
A series of porous organic polymers based on a singlet oxygen generating oxoporphyinogen (' OxP ') has been successfully prepared from a pseudotetrahedral OxP -tetraamine precursor ( OxP(4-NH 2 Bn) 4 ) by its reaction with tetracarboxylic acid dianhydrides under suitable conditions. Of the compounds studied, those containing naphthalene ( OxP-N ) and perylene ( OxP-P ) spacers, respectively, have large surface areas (~530 m2 g-1 ). On the other hand, the derivative with a simple benzene spacer ( OxP-B ) exhibits the best 1 O2 generating capability...
2024: Science and Technology of Advanced Materials
https://read.qxmd.com/read/38440397/printable-devices-for-neurotechnology
#27
REVIEW
Rita Matta, David Moreau, Rodney O'Connor
Printable electronics for neurotechnology is a rapidly emerging field that leverages various printing techniques to fabricate electronic devices, offering advantages in rapid prototyping, scalability, and cost-effectiveness. These devices have promising applications in neurobiology, enabling the recording of neuronal signals and controlled drug delivery. This review provides an overview of printing techniques, materials used in neural device fabrication, and their applications. The printing techniques discussed include inkjet, screen printing, flexographic printing, 3D printing, and more...
2024: Frontiers in Neuroscience
https://read.qxmd.com/read/38440276/scalable-synthesis-of-high-quality-reduced-graphene-oxide-with-a-large-c-o-ratio-and-its-dispersion-in-a-chemically-modified-polyimide-matrix-for-electromagnetic-interference-shielding-applications
#28
JOURNAL ARTICLE
Zahid Mehmood, Syed Aizaz Ali Shah, Saeed Omer, Ramsha Idrees, Shaukat Saeed
High-purity reduced graphene oxide (RGO or rGO) with appreciable conductivity is a desired conductive filler for lightweight polymer composites used in coatings, electronics, catalysts, electromagnetic interference (EMI) shielding, and energy storage devices. However, the intrinsic conductivity and the uniform dispersion of RGO in relatively polar matrices are challenging, leading to poor overall conductivity and performance of the composite material. The reported study improved the RGO intrinsic conductivity by increasing its C/O ratio while also simultaneously enhancing its compatibility with the polyimide (PI) matrix through ester linkages for better dispersion...
February 29, 2024: RSC Advances
https://read.qxmd.com/read/38432192/characterization-of-a-flexible-a-si-h-detector-for-in-vivo-dosimetry-in-therapeutic-x-ray-beams
#29
JOURNAL ARTICLE
Matthew James Large, Aishah Bashiri, Yashiv Dookie, Joanne McNamara, Luca Antognini, Saba Aziz, Lucio Calcagnile, Anna Paola Caricato, Roberto Catalano, Deborah Chila, Giuseppe Antonio Pablo Cirrone, Tomasso Croci, Giacomo Cuttone, Sylvain Dunand, Michele Fabi, Luca Frontini, Catia Grimani, Maria Ionica, Keida Kanxheri, Valentino Liberali, Martino Maurizio, Giuseppe Maruccio, Giovanni Mazza, Mauro Menichelli, Anna Grazia Monteduro, Arianna Morozzi, Francesco Moscatelli, Stefania Pallotta, Daniele Passeri, Maddalena Pedio, Giada Petringa, Francesca Peverini, Lorenzo Piccolo, Pisana Placidi, Gianluca Quarta, Silvia Rizzato, Federico Sabbatini, Leonello Servoli, Alberto Stabile, Cinzia Talamonti, Jonathan Emanuel Thomet, Luca Tosti, Mattia Villani, Richard James Wheadon, Nicolas Wyrsch, Nicola Zema, Marco Petasecca
BACKGROUND: The increasing use of complex and high dose-rate treatments in radiation therapy necessitates advanced detectors to provide accurate dosimetry. Rather than relying on pre-treatment quality assurance (QA) measurements alone, many countries are now mandating the use of in vivo dosimetry, whereby a dosimeter is placed on the surface of the patient during treatment. Ideally, in vivo detectors should be flexible to conform to a patient's irregular surfaces. PURPOSE: This study aims to characterize a novel hydrogenated amorphous silicon (a-Si:H) radiation detector for the dosimetry of therapeutic x-ray beams...
March 3, 2024: Medical Physics
https://read.qxmd.com/read/38424290/touchless-thermosensation-enabled-by-flexible-infrared-photothermoelectric-detector-for-temperature-pre-warning-function-of-electronic-skin
#30
JOURNAL ARTICLE
Xiaohan Guo, Xiaowei Lu, Peng Jiang, Xinhe Bao
Artificial skin, endowed with the capability to perceive thermal stimuli without physical contact, will bring innovative interactive experiences into smart robotics and augmented reality. The implementation of touchless thermosensation, responding to both hot and cold stimuli, relies on the construction of a flexible infrared detector operating in the long-wavelength infrared range to capture the spontaneous thermal radiation. This imposes rigorous requirements on the photodetection performance and mechanical flexibility of the detector...
February 29, 2024: Advanced Materials
https://read.qxmd.com/read/38422507/density-functional-theory-based-approach-for-dielectric-constant-estimation-of-soluble-polyimide-insulators
#31
JOURNAL ARTICLE
Hyunjin Park, Hyuk Choi, Jongseok Kim, Sungmi Yoo, Hyun Jung Mun, Tae Joo Shin, Jong Chan Won, Hyun You Kim, Yun Ho Kim
Evaluation of the insulating properties of polymers, such as the dielectric constant and dissipation factor, is crucial in electronic devices, including field-effect transistors and wireless communication applications. This study applies density functional theory (DFT) to predict the dielectric constant of soluble polyimides (SPIs). Various SPIs containing trifluoromethyl groups in the backbone with different pendant types, numbers, and symmetries are successfully synthesized, and their dielectric constants are evaluated and compared with the DFT-estimated values...
February 29, 2024: Journal of Physical Chemistry. B
https://read.qxmd.com/read/38419878/improvements-in-properties-of-polybenzoxazine-based-laser-induced-graphene-lig-by-alloying-with-polyimide-and-modeling-of-production-process
#32
JOURNAL ARTICLE
Ibrahim Lawan, Panuwat Luengrojanakul, Krittapas Charoensuk, Hariharan Argunam, Cheol-Hee Ahn, Sarawut Rimdusit
Laser-induced graphene (LIG) is conventionally produced from polyimide among thermosetting polymer substrates, but its flexible nature limits its tremendous potential in applications where flexibility of the substrate is not desired. Interestingly, polybenzoxazine has also been found to have potential as a substrate in LIG production. However, aside from being brittle, it has inferior char residue and thermal stability relative to polyimide, which could result in the production of LIG with inferior properties...
February 27, 2024: Nanoscale advances
https://read.qxmd.com/read/38417173/improvement-of-electrothermal-and-photothermal-properties-of-ultra-thin-graphite-film-on-oxygen-plasma-treated-polyimide-substrate
#33
JOURNAL ARTICLE
Mengshuai Ren, Bo Mao, Pei Ding, Luyang Niu, Zhi Yuan, Xuan Jia, Zhihuan Wang, Kun Xu, Junqiao Wang
Graphene and its derivatives are widely used in the field of energy conversion and management due to their excellent physical and chemical properties. In this paper, ultra-thin graphite film (GF) with thickness of 100-150 nm prepared by chemical vapor deposition (CVD) was transferred to oxygen plasma-treated polyimide (PI) substrate as flexible heating film. The electrothermal and photothermal properties of GF on PI substrates with different treatment time were studied. The experimental results show that the PI substrate pretreated by oxygen plasma can change the surface morphology of GF, increase its electrical conductivity and light absorption capacity, and significantly improve the electrothermal and photothermal properties of GF heater...
February 28, 2024: Nanotechnology
https://read.qxmd.com/read/38409202/highly-conductive-conformable-ionic-laser-induced-graphene-electrodes-for-flexible-iontronic-devices
#34
JOURNAL ARTICLE
So Young Kim, Ji Hong Kim, Kyeong Nam Kim, Hayoung Oh, Sung Myung, Do Hwan Kim
Iontronic devices, recognized for user-friendly soft electronics, establish an electrical double layer (EDL) at the interface between ion gels and electrodes, significantly influencing device performance. Despite extensive research on ion gels and diverse electrode materials, achieving a stable interfacial formation remains a persistent challenge. In this work, we report a solution to address this challenge by employing CO2 irradiation as a bottom-up methodology to directly fabricate highly conductive, conformable laser-induced graphene (LIG) electrodes on a polyimide (PI)-based ion gel...
February 26, 2024: Scientific Reports
https://read.qxmd.com/read/38404886/low-profile-700-mhz-conformal-omni-directional-antenna-for-commercial-wireless-and-safety-communication-wearable-applications
#35
JOURNAL ARTICLE
Ravi Kumar Thella, Jayendra Kumar
The 700 MHz public safety spectrum is released for commercial wireless and safety communication wearable applications (CWSC-WA). However, the 700 MHz band need a larger aperture for an efficient radiation due to a larger wavelength. In this paper, we have systematically developed a novel miniature omnidirectional 700 MHz antenna for the CWSC-WA. Over 40% miniaturization is realized by truncating the ground plane and a meander line inspired radiator compared to a conventional rectangular patch antenna. The truncation of the ground plane also yields a perfect omnidirectional radiation pattern desired for the CWSCA...
February 29, 2024: Heliyon
https://read.qxmd.com/read/38399923/preparation-of-mos-2-pda-modified-polyimide-films-with-high-mechanical-performance-and-improved-electrical-insulation
#36
JOURNAL ARTICLE
Xian Cheng, Chenxi Wang, Shuo Chen, Leyuan Zhang, Zihao Liu, Wenhao Zhang
Polyimide (PI) has been widely used in cable insulation, thermal insulation, wind power protection, and other fields due to its high chemical stability and excellent electrical insulation and mechanical properties. In this research, a modified PI composite film (MoS2 @PDA/PI) was obtained by using polydopamine (PDA)-coated molybdenum disulfide (MoS2 ) as a filler. The low interlayer friction characteristics and high elastic modulus of MoS2 provide a theoretical basis for enhancing the flexible mechanical properties of the PI matrix...
February 17, 2024: Polymers
https://read.qxmd.com/read/38399899/effect-of-water-absorption-on-electric-properties-of-temperature-resistant-polymers
#37
JOURNAL ARTICLE
Kaito Watanabe, Masahiro Kaneko, Xianzhu Zhong, Kenji Takada, Tatsuo Kaneko, Mika Kawai, Tetsu Mitsumata
The effects of water absorption on the electric resistivity and dielectric constant of polyimide (PI) and poly(ethylene terephthalate) (PET) were investigated, and the mechanism of deterioration in electrical insulation properties was discussed. The polyimides are poly(oxydianiline pyromellitimide) (PMDA-ODA) and poly(para-phenylene diamine biphenyltetracarboxydiimide) (BPDA-PDA). These polymer films were immersed in pure water for various immersion times at room temperature, and the water absorption ratio was evaluated...
February 15, 2024: Polymers
https://read.qxmd.com/read/38399841/mode-i-fatigue-and-fracture-assessment-of-polyimide-epoxy-and-silicon-epoxy-interfaces-in-chip-package-components
#38
JOURNAL ARTICLE
Pedro Morais, Alireza Akhavan-Safar, Ricardo J C Carbas, Eduardo A S Marques, Bala Karunamurthy, Lucas F M da Silva
Semiconductor advancements demand greater integrated circuit density, structural miniaturization, and complex material combinations, resulting in stress concentrations from property mismatches. This study investigates the failure in two types of interfaces found in chip packages: silicon-epoxy mold compound (EMC) and polyimide-EMC. These interfaces were subjected to quasi-static and fatigue loading conditions. Employing a compliance-based beam method, the tests determined interfacial critical fracture energy values, (GIC), of 0...
February 7, 2024: Polymers
https://read.qxmd.com/read/38399838/molecularly-mixed-composite-membranes-for-gas-separation-based-on-macrocycles-embedded-in-a-polyimide
#39
JOURNAL ARTICLE
Danilo Vuono, Gabriele Clarizia, Loredana Ferreri, Grazia Maria Letizia Consoli, Daniela Clotilde Zampino, Giuseppina Scalzo, Salvatore Petralia, Paola Bernardo
Polyimides are a polymer class that has been extensively investigated as a membrane material for gas separation owing to its interesting permselective properties in a wide range of operation temperatures and pressures. In order to improve their properties, the addition of different filler types is currently studied. p-tert -Butylcalix[n]arene macrocycles (PTBCs) with different cavity sizes (PTBC4, PTBC6, PTBC8) were used as fillers in a commercial thermoplastic polyimide, with a concentration in the range 1-9 wt%, to develop nanocomposite membranes for gas separation...
February 7, 2024: Polymers
https://read.qxmd.com/read/38398947/design-and-implementation-of-a-flexible-electromagnetic-actuator-for-tunable-terahertz-metamaterials
#40
JOURNAL ARTICLE
Shengru Zhou, Chao Liang, Ziqi Mei, Rongbo Xie, Zhenci Sun, Ji Li, Wenqiang Zhang, Yong Ruan, Xiaoguang Zhao
Actuators play a crucial role in microelectromechanical systems (MEMS) and hold substantial potential for applications in various domains, including reconfigurable metamaterials. This research aims to design, fabricate, and characterize structures for the actuation of the EMA. The electromagnetic actuator overcomes the lack of high drive voltage required by other actuators. The proposed actuator configuration comprises supporting cantilever beams with fixed ends, an integrated coil positioned above the cantilever's movable plate, and a permanent magnet located beneath the cantilever's movable plate to generate a static magnetic field...
January 31, 2024: Micromachines
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