Deformation Analysis of Roll Mold for Nano-flexible Devices

Amin Khaliq(Amin Khaliq ),Usama Tahir(Usama Tahir ),Jeong Myung Yung (Jeong Jeong) 한국마이크로전자및패키징학회 2021 마이크로전자 및 패키징학회지 Vol.28 No.4

Nanoimprint lithography (NIL) has revolutionized the fabrications of electronics, photonics, optical and biological devices. Among all the NIL processes, roll-to-roll nanoimprinting is regarded best for having the attributes of low cost, continuous, simple, and energy-efficient process for nanoscale device fabrication. However, large-area printing is limited by the master mold deformation. In this study, a finite element model (FEM) has been constructed to assess the deformation of the roll mold adhesively wrapped on the carbon fiber reinforced material (CFRP) base roll. This study also optimizes the deformations in the metallic roll mold with respect to nip-forces applied in the printing process of nano-fabrication on large scale. The numerical simulations were also conducted to evaluate the deflection in roll mold assembly due to gravity. The results have shown decreasing trend of the deformation with decreasing nip-force. Also, pressure uniformity of about 40% has been optimized by using the current numerical model along with an acceptable deflection value in the vertical axis due to gravity.

Rotor Pole Optimization of Novel Axial-Flux Brushless Doubly Fed Reluctance Machine for Torque Enhancement

Khaliq, Salman,Atiq, Shahid,Lipo, Thomas A.,Kwon, Byung-Il IEEE 2016 IEEE transactions on magnetics Vol.52 No.7

<P>This paper presents an optimal design of the rotor pole in a novel axial-flux brushless doubly fed reluctance machine (AF-BDFRM), which features higher torque and power density than its counterpart radial-flux BDFRM. The rotor span and rotor overhang lengths were the optimized parameters, with the goals of improving torque density and improving the quality of the output power, i.e., reducing the torque ripple. The optimal design process was applied to obtain the optimized shape for maximizing torque density while minimizing torque ripple in a 16 kW machine. Then, the optimal design results were verified by means of the transient 3-D finite-element analysis. Furthermore, the results of the optimally designed rotor pole were compared with those of a previously developed diamond shape. Finally, a sample prototype of one HP was selected for testing, considering the manufacturing cost and available testing facilities to verify the proper working of the novel AF-BDFRM.</P>

Assembly of polymer micelles through the sol-gel transition for effective cancer therapy

Khaliq, Nisar Ul,Oh, Keun Sang,Sandra, Febrina Carolina,Joo, Yeonhee,Lee, Juhyung,Byun, Youngro,Kim, In-San,Kwon, Ick Chan,Seo, Jae Hong,Kim, Sang Yoon,Yuk, Soon Hong Elsevier 2017 Journal of controlled release Vol.255 No.-

<P><B>Abstract</B></P> <P>Photo-induced apoptosis-targeted chemotherapy (PIATC) was designed and characterized to propose a new protocol for improved chemotherapy. Intratumoral injection was selected as the mode of administration of the anticancer drug, doxorubicin (DOX). To extend the retention time of DOX at the tumor parenchyma, <I>in-situ</I> gel formation was induced through the sol-gel transition of the Pluronic NPs containing a prodrug of DOX or a photosensitizer. The prodrug (DEVD-S-DOX) was designed to be inactive with a peptide moiety (Aspartic acid-Glutamic acid-Valine-Aspartic acid: DEVD) linked to DOX and to be cleaved into free DOX by caspase-3 expressed with apoptosis. For reactive oxygen species (ROS)-mediated apoptosis, photo-irradiation with methylene blue (MB, photosensitizer) was utilized. The sol-gel transition of the Pluronic NPs containing reactive species, DEVD-S-DOX or MB, was examined by measuring the cloud point and the gel strength in response to temperature change. ROS-mediated apoptosis was observed by measuring the ROS and membrane integrity with induced apoptosis. The <I>in vivo</I> antitumor efficacy of PIATC was measured with a cardiotoxicity assay in tumor-bearing mice.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Design of Novel Axial-Flux Dual Stator Doubly Fed Reluctance Machine

Khaliq, Salman,Modarres, Mohammad,Lipo, Thomas A.,Kwon, Byung-Il IEEE 2015 IEEE transactions on magnetics Vol.51 No.11

<P>This paper proposes a novel machine termed the axial-flux brushless doubly fed reluctance machine (AF-BDFRM) suitable for high-torque, low-speed direct drive applications. The main potential advantages of AF-BDFRM are its higher torque and power density compared with the radial-flux BDFRM. In addition, the proposed machine utilizes a bidirectional power converter of much lower rating as compared with the machine rating depending on the range of speed variation. The proposed machine axial-flux topology is composed of two stators and a reluctance iron rotor. The upper stator winding which is connected directly to the power grid, transfers active power to the grid and lower stator winding creates excitation for the machine and connects to the grid through a partially rated converter. The design principles of the proposed AF-BDFRM are studied in this paper. Furthermore, the transient 3-D finite-element analysis result of the improved design is presented.</P>

Ferroelectric seeds-induced phase evolution and large electrostrain under reduced poling field in bismuth-based composites

Khaliq, Abdul,Sheeraz, Muhammad,Ullah, Aman,Seog, Hae Jin,Ahn, Chang Won,Kim, Tae Heon,Cho, Shinuk,Kim, Ill Won Elsevier 2018 CERAMICS INTERNATIONAL Vol.44 No.11

<P><B>Abstract</B></P> <P>Bi<SUB>0.5</SUB>Na<SUB>0.5</SUB>TiO<SUB>3</SUB>-based piezoelectric ceramics have attracted great interest in actuator applications due to their high strain response; however, high driving field and large hysteresis of these materials are long-lasting obstacles for their commercial applications. Here, we use a strategy to overcome these hurdles by reducing poling field of the relaxor 0.96Bi<SUB>0.5</SUB>(Na<SUB>0.78</SUB>K<SUB>0.22</SUB>)<SUB>0.5</SUB>TiO<SUB>3</SUB>-0.04Bi(Mg<SUB>0.5</SUB>Ti<SUB>0.5</SUB>)O<SUB>3</SUB> (BNKT-0.04BMT) matrix introducing ferroelectric (BNT, BKT and BNKT) seeds (10, 15 and 20 wt%). The poling field decreases with increasing ferroelectric seeds accompanied by the transformation from ergodic relaxor to ferroelectric phase. Consequently, large normalized strains (d<SUP>*</SUP> <SUB>33</SUB> = S<SUB>max</SUB>/E<SUB>max</SUB> = 560, 469 and 450 pm/V) were recorded for BNT (15 wt%), BKT (10 wt%) and BNKT (15 wt%) seeded composites under a reduced driving field of 2.5 kV/mm. These findings indicate that ferroelectric seeds are more effective in reducing the field for strain activation which can be appropriate for actuator devices.</P>

Doxorubicin/heparin composite nanoparticles for caspase-activated prodrug chemotherapy

Khaliq, N.U.,Sandra, F.C.,Park, D.Y.,Lee, J.Y.,Oh, K.S.,Kim, D.,Byun, Y.,Kim, I.S.,Kwon, I.C.,Kim, S.Y.,Yuk, S.H. IPC Science and Technology Press 2016 Biomaterials Vol.101 No.-

<P>Caspase-activated prodrug chemotherapy is introduced and demonstrated using the composite nano particles (NPs), which deliver doxorubicin (DOX) and DEVD-S-DOX together to the tumor tissue. DEVD-S-DOX, DOX linked to a peptide moiety (DEVD), is a prodrug that is cleaved into free DOX by caspase-3 upon apoptosis. DEVD-S-DOX has no therapeutic efficacy, but it changes into free DOX with the expression of caspase-3. With the accumulation of the composite NPs in the tumor tissue by the enhanced permeation and retention (EPR) effect, a small exposure of DOX in the tumor. cells initiated apoptosis in a localized area of the tumor tissue, which induced caspase-3 activation. Cleavage of DEVD-S-DOX into free DOX by caspase-3 continued with repetitive activation of caspase-3 and cleavage of DEVD-S-DOX at the tumor site. The composite NPs were characterized with transmittance electron microscopy (TEM) and particle size analyzer. We then evaluated the nanoparticle drug release, therapeutic efficacy, and in vivo biodistribution for tumor targeting using a non-invasive live animal imaging technology and the quantification of DOX with high performance liquid chromatography. DOX-induced apoptosis-targeted chemotherapy (DIATC) was verified by in vitro/in vivo DEVD-S-DOX response to free DOX and cellular uptake behavior of the composite NPs with flow cytometry analysis. Significant antitumor efficacy with minimal cardiotoxicity was also observed, which supported DIATC for improved chemotherapy. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Large strain in Bi_0.5(Na_0.78K_0.22)_0.5TiO₃–Bi(Mg_0.5Ti_0.5)O₃ based composite ceramics under low driving field

Khaliq, Abdul,Sheeraz, Muhammad,Ullah, Aman,Lee, Jae Shin,Ahn, Chang Won,Kim, Ill Won Elsevier 2017 Sensors and actuators. A, Physical Vol.258 No.-

<P><B>Abstract</B></P> <P>The fabricated relaxor/ferroelectric composite showed relaxor and/or ferroelectric phase depending upon the weight content of added Bi<SUB>0.5</SUB>Na<SUB>0.5</SUB>TiO<SUB>3</SUB> (BNT) seeds. Bi<SUB>0.5</SUB>Na<SUB>4.5</SUB>Ti<SUB>4</SUB>O<SUB>15</SUB> large particles were processed as precursors and modified to BNT plate-like particles by means of a double molten salt method. The base material 0.96Bi<SUB>0.5</SUB>(Na<SUB>0.78</SUB>K<SUB>0.22</SUB>)<SUB>0.5</SUB>TiO<SUB>3</SUB>-0.04Bi(Mg<SUB>0.5</SUB>Ti<SUB>0.5</SUB>)O<SUB>3</SUB> (BNKT-0.04BMT) was synthesized by means of a solid state reaction technique. The 0-3 type composite of BNKT-0.04BMT powder and BNT seeds was chosen because of the compatibility between their perovskite structures. BNT perovskite seeds were added in 10, 15 and 20wt% proportions to the base BNKT-0.04BMT matrix powder. The highest content of added BNT seeds (20wt%) yielded BNKT-0.04BMT that showed ferroelectric behavior. A large electric field–induced normalized strain (S<SUB>max</SUB>/E<SUB>max</SUB> =560pm/V) was witnessed at the low driving field of 2.5kV/mm for the composition with 15wt% BNT seeds.</P> <P><B>Highlights</B></P> <P> <UL> <LI> BNT seeds were synthesized by molten salt method whereas the BNKT-BMT powder was produced using solid state reaction. </LI> <LI> The BNT seeds were used to fabricate 0–3 type particularized composites of inhomogeneous microstructures. </LI> <LI> It was observed that electric field-induced strain was greatly enhanced under low driving field. </LI> <LI> The relaxor to ferroelectric phase transition was discussed as a function of weight ratios of BNT seeds. </LI> </UL> </P>

Design and Analysis of a Dual-Stator Spoke-Type Linear Vernier Machine for Wave Energy Extraction

Khaliq, Salman,Kwon, Byung-il The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.6

In this paper, a dual-stator, spoke-type linear vernier machine (DSSLVM) for wave energy extraction application was proposed. This machine is capable of producing a competitively high thrust force and force density at a low operation speed in direct drive systems. The operation principal and working of the proposed DSSLVM were studied. The stator core height is adjusted to improve the overall force density of the proposed machine while reducing the force ripple. To evaluate the advantages of the proposed DSSLVM, the main performance was compared with that of a recently developed linear primary permanent magnet vernier machine (LPPMVM). The proposed machine exhibited greater thrust force and force density, an improved power factor and lower force ripple with the same permanent magnet (PM) volume compared to the LPPMVM.

Effect of Plant Factors, Sugar Contents, and Control Methods on the Top Borer (Scirpophaga nivella F.) Infestation in Selected Varieties of Sugarcane

KHALIQ, Abdul,Muhammad ASHFAQ,Waseem AKRAM,최종경,이종진 한국곤충학회 2005 Entomological Research Vol.35 No.3

Sugarcane (Saccharum officinarum L.) varieties CP-43/33 and L-118 susceptible, BF-162 and SPSG-26 resistant while CP-72/2086 as intermediate were screened for studies on top borer, Scirpophaga nivella Fabricus (Pyralidae: Lepidoptera). Morpho-physio chemical plant factors as well as quality of sugar were examined to elucidate the relationship between pest infestations.The observations on leaf thickness 0.735* and moisture contents 0.771* showed positive and significant correlation with the pest infestation at tillering stage. Total minerals, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents manifested positive and significant correlation with the pest infestation. Phosphorous, carbohydrates, fats and zinc produced significant and adverse effect on the pest infestation at tillering stage. Zinc contents with contrasting behaviors appeared to be the most important character with co-efficient value of 0.764 followed by ferrous with positive sign. The effect of borer infestation was significantly negative on pol (sucrose), Brix contents (total soluble solids), and CCS (commercial cane sugar). The coefficient of determination value was 0.821, obtained by computing fiber content, pol, Brix and CCS factors together for multivariate regression models. Application of trash mulching at the time of sowing proved to be the most effective treatment with minimum infestation (3.91%) of borer and maximum protection level (62.87%) followed by Furadan., removal of dead hearts± spike thrust, hand collection of egg masses, and cutting of shoots at 15 days interval.

The multilayer nanoparticles for deep penetration of docetaxel into tumor parenchyma to overcome tumor microenvironment

Khaliq, N.U.,Park, D.Y.,Lee, J.Y.,Joo, Y.,Oh, K.S.,Kim, J.S.,Kim, J.S.,Kim, I.S.,Kwon, I.C.,Yuk, S.H. Elsevier 2016 Colloids and surfaces Biointerfaces Vol.146 No.-

<P>Deep penetration of the anticancer drug, docetaxel (DTX), into tumor parenchyma was demonstrated to achieve improved chemotherapy. For this purpose, a multistage nanostructure was designed and characterized using the multilayer nanoparticles (NPs). The multilayer NPs had a core/shell structure. The core was composed of the DTX-loaded Pluronic NPs (diameter: 12 nm) that were transferred into the inner side of vesicles to form the vesicle NPs. Forster resonance energy transfer (FRET) in the NPs was observed to verify the incorporation of the DTX-loaded Pluronic NPs into the inner side of the vesicles during the formation of the vesicle NPs. Subsequently, the vesicle NPs were stabilized through Pluronic-lipid bilayer interaction to form the multilayer NPs. To examine the morphology and size distribution of the multi layer NPs, transmittance electron microscopy and dynamic light scattering were used. In vitro release behavior and toxicity were observed to verify the functionality of the multilayer NPs as nanocarriers for cancer therapy. Multistage functionality was evaluated by cellular uptake and tissue distribution behaviors of the multilayer NPs. The biodistribution of the multilayer NPs and their antitumor efficacy were also observed to understand the role of multistage functionality for improved chemotherapy. (C) 2016 Elsevier B.V. All rights reserved.</P>