@article{islam_liu_choi_guo_ryu_2022, title={Physics-based Computational Method Predicting the Dielectric Properties of Polymer Nanocomposites}, volume={4}, ISSN={["1573-4897"]}, url={http://dx.doi.org/10.1007/s10443-022-10026-3}, DOI={10.1007/s10443-022-10026-3}, number={4}, journal={APPLIED COMPOSITE MATERIALS}, publisher={Springer Science and Business Media LLC}, author={Islam, Md Didarul and Liu, Sipan and Choi, Daniel and Guo, Zhanhu and Ryu, Jong Eun}, year={2022}, month={Apr} }
 @article{islam_perera_black_phillips_chen_hodges_jackman_liu_kim_zikry_et al._2022, title={Template‐Free Scalable Fabrication of Linearly Periodic Microstructures by Controlling Ribbing Defects Phenomenon in Forward Roll Coating for Multifunctional Applications}, volume={9}, ISSN={2196-7350 2196-7350}, url={http://dx.doi.org/10.1002/admi.202201237}, DOI={10.1002/admi.202201237}, abstractNote={Periodic micro/nanoscale structures from nature have inspired the scientific community to adopt surface design for various applications, including superhydrophobic drag reduction. One primary concern of practical applications of such periodic microstructures remains the scalability of conventional microfabrication technologies. This study demonstrates a simple template-free scalable manufacturing technique to fabricate periodic microstructures by controlling the ribbing defects in the forward roll coating. Viscoelastic composite coating materials are designed for roll-coating using carbon nanotubes (CNT) and polydimethylsiloxane (PDMS), which helps achieve a controllable ribbing with a periodicity of 114–700 µm. Depending on the process parameters, the patterned microstructures transition from the linear alignment to a random structure. The periodic microstructure enables hydrophobicity as the water contact angles of the samples ranged from 128° to 158°. When towed in a static water pool, a model boat coated with the microstructure film shows 7%–8% faster speed than the boat with a flat PDMS film. The CNT addition shows both mechanical and electrical properties improvement. In a mechanical scratch test, the cohesive failure of the CNT-PDMS film occurs in ≈90% higher force than bare PDMS. Moreover, the nonconductive bare PDMS shows sheet resistance of 747.84–22.66 Ω □−1 with 0.5 to 2.5 wt% CNT inclusion.}, number={27}, journal={Advanced Materials Interfaces}, publisher={Wiley}, author={Islam, Md Didarul and Perera, Himendra and Black, Benjamin and Phillips, Matthew and Chen, Muh‐Jang and Hodges, Greyson and Jackman, Allyce and Liu, Yuxuan and Kim, Chang‐Jin and Zikry, Mohammed and et al.}, year={2022}, month={Aug}, pages={2201237} }
 @inproceedings{islam_liu_derov_urbas_ku_sihn_smith_boyd_kim_sanghera_et al._2021, title={Highly Efficient Mid-Wavelength Infrared (MWIR) Polarizer by ORMOCHALC Composite With Improved Thermomechanical Stability and Spectral Selectivity}, url={http://dx.doi.org/10.1115/imece2021-70843}, DOI={10.1115/imece2021-70843}, abstractNote={Abstract Mid-wavelength infrared (MWIR, λ = 3–5 μm) materials are of great importance due to their applications in optical sensors and devices for military, industry, and non-invasive medical diagnostics. Specifically, MWIR polarimetry has significantly improved biometric recognition and camouflaged detection. Most commercial polarizers are based on expensive inorganic materials that are heavy, fragile, and brittle. Thus a suitable polymeric material for MWIR optics is highly desired. Herein, sulfur-based organically modified chalcogenides (ORMOCHALC) polymers have been utilized to fabricate MWIR polarizers by a simple thermal imprinting method followed by Ay deposition. A parametric study to choose suitable geometry for the polarizer was conducted, and highly efficient devices were designed that possess competitive extinction coefficients to the commercial polarizers. However, a significant limitation of the ORMOCHALC polymer is that to increase the refractive index of the polymer, the chalcogenide (i.e., S) content needs to be increased, which results in reduced Young’s modulus and lower glass transition temperature. This decayed thermomechanical stability compromises the structural integrity of ORMOCHALC optical devices. In addition to polymeric MWIR polarizer fabrication, composite materials were also synthesized and characterized for future MWIR device fabrications. Poly(S-r-DIB) was reinforced with zinc sulfide nanoparticles to simultaneously improve the refractive index and the thermomechanical properties. The addition of ZnS nanoparticles significantly improved the glass transition temperature (Tg) of the ORMOCHALC (9.6 °C to 31.4 °C), and the refractive index (Δn = 6.6 %). Then, a figure of merit subwavelength wire-grid polarizers was also analyzed based on the optically and mechanically reinforced composites. If fabricated, nanoparticles reinforced polarizers will possess superior structural integrity due to higher glass transition temperature. Moreover, the polarizers show a spectral selectivity as the resonance wavelength of the transmitted-reflected curve was redshifted to larger wavelengths for ZnS reinforced ORMOCHALC composite. These polarizers with superior extinction coefficient, spectral selectivity, and improved thermomechanical stability demonstrate a border implementation opportunity in the MWIR optics.}, booktitle={Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications}, publisher={American Society of Mechanical Engineers}, author={Islam, Md Didarul and Liu, Sipan and Derov, John and Urbas, Augustine M. and Ku, Zahyun and Sihn, Amy and Smith, Evan M. and Boyd, Darryl A. and Kim, Woohong and Sanghera, Jasbinder S. and et al.}, year={2021}, month={Nov} }
 @inproceedings{liu_islam_ku_urbas_derov_boyd_kim_sanghera_ryu_2021, title={Novel Nanocomposite Refractive Index Tuning Mechanism Based on Controlling Embedded Particle Morphology}, url={http://dx.doi.org/10.1115/imece2021-70064}, DOI={10.1115/imece2021-70064}, abstractNote={Abstract This study investigates the embedded nanoparticles’ morphology and distribution effects on the effective refractive index (RI) of composite. The study is based on the FEA model for the Fabry-Pérot interference cavity made from the nanocomposite film. The composites’ effective RI can be derived from the simulation reflection spectrum. In constant particle volume fraction condition, the embedded particles with a larger diameter, locating at the region with high electric field and having longer side length along the electric field oscillating direction, are identified as the factors to reinforce the effective RI. For 4 μm incident light-wave, as controlling the diameter from 24.8 nm to 212 nm, distribution from middle-gathered (high electric field region) to top-bottom gathered (low electric field region), and the rectangular cylinder particle shortest side along electric field oscillating direction to longest side along electric field oscillating direction, the effective RI increasing from 1.687 to 1.719, 1.638 to 1.745 and 1.66 to 1.901, respectively. The underlying RI shifting principle is recognized from the light scattering loss by embedded nanoparticles. This discovering provides one novel idea for next-generation real-time RI tuning structure and device.}, booktitle={Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications}, publisher={American Society of Mechanical Engineers}, author={Liu, Sipan and Islam, Md Didarul and Ku, Zahyun and Urbas, Augustine M. and Derov, John and Boyd, Darryl A. and Kim, Woohong and Sanghera, Jasbinder S. and Ryu, Jong E.}, year={2021}, month={Nov} }
 @article{liu_islam_ku_boyd_zhong_urbas_smith_derov_nguyen_kim_et al._2021, title={Novel computational design of high refractive index nanocomposites and effective refractive index tuning based on nanoparticle morphology effect}, volume={223}, ISSN={["1879-1069"]}, url={https://doi.org/10.1016/j.compositesb.2021.109128}, DOI={10.1016/j.compositesb.2021.109128}, abstractNote={This study introduces a method to predict the refractive index (RI) of nanocomposites with the Finite Elements Analysis (FEA) based on the Fabry-Pérot interference. The efficacy was verified by comparing the estimated composites’ RI with the available data in the literature. In the experimental verification, the FEA-based prediction showed closer results with the measurement as compared to the effective medium approximation (EMA) approaches, which are prevalently used to predict the physical properties of nanocomposites. Due to the modeling capability, the FEA-method could investigate the effect of the nanoparticle morphology (particle size, shape, and orientation) and distribution. Large particle size, particle agglomeration in high electric-field amplitude region, and particle elongation along the light oscillating direction are found to be the major factors to enhance the RI of composites. The underlying mechanism of RI changing is attributed to the light scattering by embedded nanoparticles, which provides one potential real-time RI tuning schematic.}, journal={COMPOSITES PART B-ENGINEERING}, publisher={Elsevier BV}, author={Liu, Sipan and Islam, Md Didarul and Ku, Zahyun and Boyd, Darryl A. and Zhong, Yaxu and Urbas, Augustine M. and Smith, Evan and Derov, John and Nguyen, Vinh Q. and Kim, Woohong and et al.}, year={2021}, month={Oct} }
 @article{liu_islam_ku_urbas_boyd_kim_sanghera_ryu_2021, title={The polymer nanocomposites embedded particles size and agglomeration effect on the effective refractive index tuning}, volume={11802}, ISSN={["1996-756X"]}, url={http://dx.doi.org/10.1117/12.2594382}, DOI={10.1117/12.2594382}, abstractNote={The polymer nanocomposites have attracted increasing attention in the optical components that are miniaturized and integrated with wearable or portable electronics due to the polymer processibility and the tunability of the refractive index (RI) by adding nanoparticles. However, the lack of models predicting the composites’ RI attributed to the morphology, physical properties, as well as volume fraction of the nanoparticles poses difficulties in the design. This study investigates the effect of the size and agglomeration condition of the nanoparticles on the effective RI based on a Finite Element Analysis (FEA) method simulating the Fabry-Perot resonance within the composite film. The result showed that larger particles (or particle clusters) could reinforce the RI of nanocomposites compared with the well-dispersed small particles. The particle-cluster model had lower RI than the single-solid-particle model with the same effective particle diameter, demonstrating that the particle cluster provides less scattering intensity than the single-solid-particle.}, journal={NANOENGINEERING: FABRICATION, PROPERTIES, OPTICS, THIN FILMS, AND DEVICES XVIII}, publisher={SPIE}, author={Liu, Sipan and Islam, Md Didarul and Ku, Zahyun and Urbas, Augustine M. and Boyd, Darryl A. and Kim, Woohong and Sanghera, Jasbinder S. and Ryu, Jong E.}, editor={Park, Wounjhang and Attias, André-Jean and Panchapakesan, BalajiEditors}, year={2021} }
 @inproceedings{islam_liu_derov_urbas_ku_boyd_kim_sanghera_nguyen_myers_et al._2021, title={Tunable mid-wavelength infrared (MWIR) polarizer by ORMOCHALC composite with improved thermomechanical stability}, url={http://dx.doi.org/10.1117/12.2594342}, DOI={10.1117/12.2594342}, abstractNote={Mid-wavelength infrared (MWIR, &lambda; = 3 – 5 &mu;m) materials are of great importance due to their applications in optical sensors and devices for military, industry, and non-invasive medical diagnostics. Specifically, MWIR polarimetry are used in biometric recognition and camouflaged detection. Recently, sulfur based organically modified chalcogenides (ORMOCHALC) polymers have been utilized to fabricate MWIR polarizers with competitive extinction coefficient to commercial polarizers, which are mostly made of expensive, brittle, and heavy inorganic materials. On the other hand, to adjust or reinforce the refractive index of the polymer, the chalcogenide content (i.e., sulfur, selenium) needs to be increased, which may result in adverse effects on the thermomechanical characteristics, including Young's modulus and lower glass transition temperature. This reduced thermomechanical stability compromises the structural integrity of ORMOCHALC-based optical devices. In this study, an ORMOCHALC polymer, poly(S–<i>r</i>–DIB), was reinforced with the zinc sulfide (ZnS) nanoparticles to simultaneously improve the refractive index and the thermomechanical properties. The addition of 20 wt% ZnS nanoparticles improves the pure polymer's glass transition temperature (<i>T</i><sub>g</sub>) from 9.6 &deg;C to 31.4 &deg;C, and the refractive index by &Delta;<i>n</i>= 6.58 %. Then, subwavelength wire-grid polarizers were fabricated based on the pure ORMOCHALC first by a simple thermal imprinting method followed by metal deposition. The resulted MWIR polarizer showed a high extinction coefficient which is comparable with commercial polarizers. However, the structural integrity of the polarizers was compromised due to lower glass transition temperature. Finally, finite element analysis was conducted on the possible wire-grid polarizer fabrication utilizing optically and mechanically reinforced composites, as demonstrated in this study. If fabricated, these nanoparticles reinforced polarizers will possess superior structural integrity compared to ORMOCHALC polarizers. Moreover, these polarizers show a spectral selectivity as the transmission curve's resonance wavelength depends on the composite's refractive index, which is tunable by controlling the nanoparticles content. The resonance peak redshifted from 3.12 &mu;m to 3.3 &mu;m for the pure polymer to 20% ZnS reinforced ORMOCHALC polarizer. The extinction coefficient of the polarizer also improved in multiple wavelength bands in the MWIR. These polarizers with superior extinction coefficient, spectral selectivity, and improved thermomechanical stability demonstrate a broader prospect in MWIR optics.}, booktitle={Plasmonics: Design, Materials, Fabrication, Characterization, and Applications XIX}, publisher={SPIE}, author={Islam, Md Didarul and Liu, Sipan and Derov, John S. and Urbas, Augustine M. and Ku, Zahyun and Boyd, Darryl A. and Kim, Woohong R. and Sanghera, Jasbinder S. and Nguyen, Vinh Q. and Myers, Jason D. and et al.}, editor={Lu, Yu-Jung and Tanaka, Takuo and Tsai, Din PingEditors}, year={2021}, month={Aug} }
 @article{islam_kim_ko_ku_boyd_smith_nguyen_myers_baker_kim_et al._2020, title={Design of High Efficient Mid‐Wavelength Infrared Polarizer on ORMOCHALC Polymer}, volume={305}, ISSN={1438-7492 1439-2054}, url={http://dx.doi.org/10.1002/mame.202000033}, DOI={10.1002/mame.202000033}, abstractNote={While an organically modified chalcogenide (ORMOCHALC) can be used to fabricate a polymeric mid-wavelength infrared (MWIR) polarizer with competitive extinction ratio compared to the commercial wire-grid polarizers, which are composed of fragile inorganic materials, there is still a knowledge gap regarding the systematic design process to obtain high transmission efficiency and extinction ratio. To this end, a computational parameter study for design optimization is conducted with the geometric parameters of the bilayer grating ORMOCHALC polarizer. The computational study shows that the Fabry–Pérot cavity is the primary mechanism that determines the transmission behaviors and the extinction ratio. A bilayer grating design, guided by the parameter study, is realized through the thermal nanoimprint and metal deposition processes. The extinction ratios measured with the Fourier-transform infrared are 245, 304, and 351 at the wavelength of 3, 4, and 5 µm, respectively. Compared to the state-of-the-art of the polymeric MWIR linear polarizers, the extinction ratio is improved by 1.4 times, and the transmission efficiency is increased by 2.5 times. Theoretical analysis with the multiple-layer model based on the transfer matrix method predicts a matched transmission behavior with the experiment and a full-wave electromagnetic simulation.}, number={5}, journal={Macromolecular Materials and Engineering}, publisher={Wiley}, author={Islam, Md Didarul and Kim, Jun Oh and Ko, Yeongun and Ku, Zahyun and Boyd, Darryl A. and Smith, Evan M. and Nguyen, Vinh Q. and Myers, Jason D. and Baker, Colin C. and Kim, Woohong and et al.}, year={2020}, month={Mar}, pages={2000033} }
 @article{islam_liu_boyd_zhong_nahid_henry_taussig_ko_nguyen_myers_et al._2020, title={Enhanced mid-wavelength infrared refractive index of organically modified chalcogenide (ORMOCHALC) polymer nanocomposites with thermomechanical stability}, volume={108}, ISSN={["1873-1252"]}, url={http://dx.doi.org/10.1016/j.optmat.2020.110197}, DOI={10.1016/j.optmat.2020.110197}, abstractNote={Abstract Organically modified chalcogenide (ORMOCHALC) polymers have proven to be alternatives to the conventional inorganic materials for mid-wavelength infrared (MWIR, λ = 3–5 μm) optical components. While the refractive index of ORMOCHALC can be reinforced by the content of chalcogenides such as sulfur (S) and selenium (Se), the increased portion of the S or Se deteriorate the thermomechanical stabilities. As a remedy, this study utilizes ZnS nanoparticles to reinforce both optical and thermomechanical properties of the sulfur-based ORMOCHALC polymer, poly(S-random-1,3-diisopropenylbenzene). The refractive index n and extinction coefficient k of the nanocomposites were characterized by Infrared Variable Angle Spectroscopic Ellipsometry (IR-VASE). The results show a significant increment in the refractive index of Δn = 6.58% at the wavelength of 4 μm by adding 20 wt% ZnS (or 7.29 vol%) in the ORMOCHALC polymer. The low extinction coefficient of the nanocomposites (}, journal={OPTICAL MATERIALS}, author={Islam, Md Didarul and Liu, Sipan and Boyd, Darryl A. and Zhong, Yaxu and Nahid, Masrur Morshed and Henry, Reece and Taussig, Laine and Ko, Yeongun and Nguyen, Vinh Q. and Myers, Jason D. and et al.}, year={2020}, month={Oct} }
 @article{kim_renteria‐marquez_islam_chavez_rosales_ahsan_tseng_love_lin_2019, title={Fabrication of bulk piezoelectric and dielectric BaTiO <inf>3</inf> ceramics using paste extrusion 3D printing technique}, volume={102}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85058797928&partnerID=MN8TOARS}, DOI={10.1111/jace.16242}, abstractNote={A simple and facile method was developed to fabricate functional bulk barium titanate (BaTiO3, BT) ceramics using the paste extrusion 3D printing technique. The BT ceramic is a lead-free ferroelectric material widely used for various applications in sensors, energy storage, and harvesting. There are several traditional methods (eg, tape casting) to process bulk BT ceramics but they have disadvantages such as difficult handing without shape deformation, demolding, complex geometric shapes, expansive molds, etc. In this research, we utilized the paste extrusion 3D printing technique to overcome the traditional issues and developed printable ceramic suspensions containing BT ceramic powder, polyvinylidene fluoride (PVDF), N,N-dimethylformamide (DMF) through simple mixing method and chemical formulation. This PVDF solution erformed multiple roles of binder, plasticizer, and dispersant for excellent manufacturability while providing high volume percent and density of the final bulk ceramic. Based on empirical data, it was found that the maximum binder ratio with good viscosity and retention for desired geometry is 1:8.8, while the maximum BT content is 35.45 vol% (77.01 wt%) in order to achieve maximum density of 3.93 g/cm3 (65.3%) for 3D printed BT ceramic. Among different sintering temperatures, it was observed that the sintered BT ceramic at 1400°C had highest grain growth and tetragonality which affected high performing piezoelectric and dielectric properties, 200 pC/N and 4730 at 103 Hz respectively. This paste extrusion 3D printing technique and simple synthesis method for ceramic suspensions are expected to enable rapid massive production, customization, design flexibility of the bulk piezoelectric and dielectric devices for next generation technology.}, number={6}, journal={Journal of the American Ceramic Society}, publisher={Wiley}, author={Kim, Hoejin and Renteria‐Marquez, Anabel and Islam, Md Didarul and Chavez, Luis A. and Rosales, Carlos A. Garcia and Ahsan, Md Ariful and Tseng, Tzu‐Liang Bill and Love, Norman D. and Lin, Yirong}, year={2019}, pages={3685–3694} }
 @article{berndt_hwang_islam_sihn_urbas_ku_lee_czaplewski_dong_shao_et al._2019, title={Poly(sulfur-random-(1,3-diisopropenylbenzene)) based mid-wavelength infrared polarizer: Optical property experimental and theoretical analysis}, volume={176}, ISSN={["1873-2291"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85066071701&partnerID=MN8TOARS}, DOI={10.1016/j.polymer.2019.05.036}, abstractNote={Development of polymer based mid-wavelength infrared (MWIR) optics has been limited mainly due to high optical loss of organic polymers used in general optical components. In this study, a MWIR polarization grating based on a sulfuric polymer poly(sulfur-random-(1,3-diisopropenylbenzene)) with a low loss in the MWIR range was fabricated using a simple two-step process: imprint and metal deposition. Fourier-transform infrared (FTIR) spectroscopy measurement showed that this polymeric MWIR polarizer selectively transmitted the polarized IR in transverse magnetic (TM) mode over the transverse electric (TE) mode at normal incidence. The measured extinction ratios (η = The ratio of transmissions in TM and TE) were 208, 176, and 212 at the wavelength of 3, 4, and 5 μm, respectively. The computational simulation and analytical model confirmed that the enhanced TM transmission efficiency and η followed a Fabry-Pérot (FP) resonance mode within the created sulfuric polymer film. This polymeric MWIR polarizer demonstrated a great potential for broader applications in IR photonics to realize low-cost and durable optical components.}, journal={POLYMER}, publisher={Elsevier BV}, author={Berndt, Aaron J. and Hwang, Jehwan and Islam, Md Didarul and Sihn, Amy and Urbas, Augustine M. and Ku, Zahyun and Lee, Sang Jun and Czaplewski, David A. and Dong, Mengyao and Shao, Qian and et al.}, year={2019}, month={Aug}, pages={118–126} }
 @article{tanvir_islam_ahmed_2017, title={Analysis of thermoelastic characteristics in a thick walled FGM cylinder}, volume={1919}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85040996392&partnerID=MN8TOARS}, DOI={10.1063/1.5018548}, abstractNote={This study is concerned with the behavior of stress and strain in a thick walled functionally graded material (FGM) cylinder under internal pressure. The incompatible eigenstrain and equivalent eigenstrain developed in the cylinder, are taken into account. As a demonstration, a TiC/Al2O3 FGM cylinder is considered and different components of stress and strain are presented in order to study the effects of internal pressure, temperature difference (between room and sintering temperature), cylinder wall thickness and material distribution. The numerical result presented here shows that the thermoelastic characteristic like stress and strain of an FGM cylinder is significantly influenced by some of the above-mentioned parameters and can be controlled by properly controlling these parameters.}, journal={AIP Conference Proceedings}, publisher={Author(s)}, author={Tanvir, A. N. M. and Islam, Md. Didarul and Ahmed, Faisal}, year={2017} }
 @article{kim_torres_islam_islam_chavez_garcia rosales_wilburn_stewart_noveron_tseng_et al._2017, title={Increased piezoelectric response in functional nanocomposites through multiwall carbon nanotube interface and fused-deposition modeling three-dimensional printing}, volume={7}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85034586130&partnerID=MN8TOARS}, DOI={10.1557/mrc.2017.126}, number={4}, journal={MRS Communications}, author={Kim, H. and Torres, F. and Islam, M.T. and Islam, M.D. and Chavez, L.A. and Garcia Rosales, C.A. and Wilburn, B.R. and Stewart, C.M. and Noveron, J.C. and Tseng, T.-L.B. and et al.}, year={2017}, pages={960–966} }
 @article{kim_torres_islam_islam_chavez_rosales_wilburn_stewart_noveron_tseng_et al._2017, title={Increased piezoelectric response in functional nanocomposites through multiwall carbon nanotube interface and fused-deposition modeling three-dimensional printing – CORRIGENDUM}, volume={7}, DOI={10.1557/mrc.2017.129}, number={4}, journal={MRS Communications}, publisher={Cambridge University Press (CUP)}, author={Kim, Hoejin and Torres, Fernando and Islam, Tariqul and Islam, Didarul and Chavez, Luis A. and Rosales, Carlos A. Garcia and Wilburn, Bethany R. and Stewart, Calvin M. and Noveron, Juan C. and Tseng, Tzu-Liang B. and et al.}, year={2017}, pages={974–974} }