Article
Nanoscience & Nanotechnology
Zizheng Wang, Hao Jiang, Guangfu Wu, Yi Li, Teng Zhang, Yi Zhang, Xueju Wang
Summary: This study reports a method for programmable three-dimensional microfluidic structures assembled from polydimethylsiloxane (PDMS) and shape-memory polymers (SMPs). The approach allows for the creation of diverse geometries and the ability to program temporary shapes, with well-maintained fluid flow during deformation and shape recovery.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Physics, Multidisciplinary
Yonglong Jin, Yaoyao Yin, Danzhu Wei, Tian Xu, Chaonan Wang, Meifeng Xu, Cong Peng
Summary: A liquid-core metal-cladding waveguide (LCMW) structure was proposed for optical trapping of SiO2 colloid particles, and factors such as the reflectivity of the guiding layer, light-off time, and sample refractive index were found to influence the time required for the SiO2 particles to reach a stable state during self-assembly.
Article
Optics
Joao M. Maia, Duarte Viveiros, Vitor A. Amorim, P. V. S. Marques
Summary: This work focuses on the fabrication of straight silica-core liquid-cladding suspended waveguides using fs-laser micromachining in a microfluidic channel. The waveguides are further smoothed and reshaped into a circular cross-section through post-processing thermal treatment. The study shows that the suspended waveguides have adjustable insertion losses and allow for the reconfiguration of the mode profile, enhancing the evanescent interaction between light and analyte.
OPTICS AND LASERS IN ENGINEERING
(2022)
Article
Polymer Science
Yuqi Xie, Jiachen Han, Tian Qin, Xuyang Ge, Xihan Wu, Lu Liu, Xubin Wu, Yunji Yi
Summary: A hybrid-integrated thermo-optic switch was designed and simulated in this study, utilizing the large thermo-optical coefficient of polymer materials. By introducing the air trench structure and optimizing the heating region's structural parameters, the power consumption was significantly reduced. This device can be applied to hybrid integration fields such as array switches and ROADMs.
Article
Engineering, Electrical & Electronic
Lu Xue, Xinzhi Sheng, Shuqin Lou, Guozhong Zhao, Shuai Yang, Zhen Xing, Haoqiang Jia
Summary: A novel high-birefringence and low-loss hollow-core antiresonant THz waveguide is proposed and experimentally demonstrated. Simulation results show high birefringence and low loss in the waveguide, which is verified through experimental measurements. This waveguide achieves the highest birefringence and relatively low loss in current THz waveguides.
IEEE TRANSACTIONS ON TERAHERTZ SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Yujie Kong, Xuewen Shu
Summary: The 2D vector bending fiber sensor demonstrated in this study is based on a femtosecond laser inscribed hybrid cladding waveguide structure, offering high sensitivity, a relatively large curvature range, and 2D orientation identification. This sensor has the potential to be applied in public infrastructure health monitoring and wearable artificial devices.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Li Chen, Yao Xiao, Qinglin Wu, Xiaoxiao Yan, Peng Zhao, Jian Ruan, Jianzhen Shan, Dong Chen, David A. Weitz, Fangfu Ye
Summary: Hierarchical emulsions are significant for both scientific research and practical applications. A versatile method using microfluidic 3D droplet printing has been developed to design hierarchical emulsions with tunable core characteristics, serving as excellent templates for functional materials development. This method offers a powerful platform with improved simplicity and flexibility for designing hierarchical emulsions and functional materials.
Article
Nanoscience & Nanotechnology
Robert A. A. Stavins, William P. P. King
Summary: A miniature elastomer bellows pump that can be integrated with a microfluidic cartridge is presented in this paper to address the challenge of efficient pumping in microfluidics. The pump features three-dimensional geometries enabled by additive manufacturing in elastomer materials. By parameterizing the design space, fabricating 146 pumps, and characterizing their mechanical properties and fluid-pumping performance, the research explores the relationship between mechanical design parameters and pump performance.
MICROFLUIDICS AND NANOFLUIDICS
(2023)
Article
Optics
Rahul Panchal, Aloka Sinha
Summary: We propose a multimode planar waveguide with a polymer core and an electrically tunable liquid crystal cladding. The waveguide is fabricated using a cost-effective photolithography technique. The refractive index of the cladding can be controlled by applying voltage, which affects the propagation of TM modes in the core. Experimental results show a low threshold voltage and a high extinction ratio, making this device suitable for low threshold electro-optic switching and optical attenuation.
OPTICS COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Niko Kimura, Masatoshi Maeki, Kosuke Sasaki, Yusuke Sato, Akihiko Ishida, Hirofumi Tani, Hideyoshi Harashima, Manabu Tokeshi
Summary: The study developed a three-dimensional symmetrically assembled microfluidic device named the 3D-iLiNP device with the aim of precise size control of large-sized LNPs. Through computational fluid dynamics simulation, the device was designed and demonstrated to improve the LNP size distribution. Results showed that LNPs with sizes between 90 and 120 nm exhibited higher gene silencing activity compared to other sizes. The 3D-iLiNP device is expected to enhance DDS performance by accurately controlling the size of LNPs.
Article
Chemistry, Analytical
Yang Zhou, Jiao Wang, Ting Liu, Man Wu, Yuwei Lan, Chunping Jia, Jianlong Zhao
Summary: Microfluidic impedance cytometry is a label-free, low-cost and portable solution for cell analysis. A miniaturized flow cytometer based on a 3D hydrodynamic focusing mechanism is designed and characterized. The use of an adaptive sheath effectively concentrates the sample and increases the signal-to-noise ratio of the particle impedance pulse. The system showed accurate representation of the particle impedance characteristic distribution and can be conveniently used to monitor cell status.
Article
Engineering, Electrical & Electronic
Taiji Sakamoto, Ryota Imada, Kazuhide Nakajima
Summary: This paper proposes cross-sectional design guidelines suitable for a power efficient cladding-pumped coupled multi-core erbium-doped fiber amplifier (MC-EDFA). Numerical calculations and experimental verification were conducted to investigate the optimal core-to-cladding ratio (R-cc) for achieving high power conversion efficiency (PCE) in different operational bandwidths (C- or L-band) of the amplifier. The results showed that the PCE in the C-band amplifier improves as R-cc increases, whereas the PCE in the L-band amplifier maximizes at a specific R-cc value.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Alvin Modin, Biswarup Ash, Kelsey Ishimoto, Robert L. Leheny, Francesca Serra, Hillel Aharoni
Summary: This study introduces a theoretical framework to quantitatively predict the connectivity and shape of disclination lines in liquid crystals. Through experimental testing and computer simulations, it is found that certain parameters can tune the curvature of disclination lines. This research provides a powerful method to understand and control defect lines in liquid crystals.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Chemistry, Analytical
Chang Liu, Xiaofeng Liu, Qiang Tang, Wenhao Zhou, Yan Ma, Zheng Gong, Junhao Chen, Huai Zheng, Sang Woo Joo
Summary: An active and precise method for three-dimensional droplet manipulation is introduced in this study. By modulating the local electrostatic force and using a flexible plate electrode, the vertical motion of droplets can be controlled, and various manipulations such as levitation, transport, merging, and mixing can be effectively performed.
ANALYTICAL CHEMISTRY
(2022)
Article
Physics, Multidisciplinary
Pan Guo, Danting Cui, Qiaofeng Dai, Hongdao Cheng, Jianhui Yu, Heyuan Guan, Yunhan Luo, Huihui Lu, Yi Xiao, Yongchun Zhong, Wenguo Zhu, Zhe Chen
Summary: This article presents an ultrafast humidity micro-fiber sensor with MoS2 cladding and a three-dimensional network structure. The sensor exhibits high sensitivity and rapid response and recovery times, making it suitable for a wide range of humidity levels. It has great potential for application in various fields such as chemical processing and medical diagnostics.
FRONTIERS IN PHYSICS
(2022)
Article
Mechanics
Qian Mao, Jiazhen Zhao, Yingzheng Liu, Hyung Jin Sung
Summary: The hydrodynamic benefits of fixed and flapping pectoral fins were explored using the penalty immersed boundary method. It was found that the vortices generated by the pectoral fins increase the pressure difference between the upper and lower sides of the plate, resulting in an enhancement of both the cruising speed and thrust. Horizontal flapping pectoral fins with low flapping frequency enhance the propulsive efficiency. Flexible flapping fins enhance the cruising speed. Additionally, the presence of one flapping fin on one side of the flexible plate induces asymmetrical heaving of the plate and increases the lateral forces, which might help fish achieve turning and maintain balance in perturbed flows.
Article
Mechanics
Jiazhen Zhao, Qian Mao, Guang Pan, QiaoGao Huang, Hyung Jin Sung
Summary: The hydrodynamics of a self-propelled flexible plate near the ground were investigated. The interaction between the plate and the ground generates a strong vortex, leading to an increase in cruising speed. The aspect ratio and gap distance from the ground also play a role in determining the performance of the plate.
Letter
Mechanics
Guo-Zhen Ma, Chun-Xiao Xu, Hyung Jin Sung, Wei-Xi Huang
Summary: This paper proposes a roughness scaling method based on the direct numerical simulation of turbulent channel flow over three-dimensional sinusoidal rough walls in a transitionally rough regime. A new coupling scale is defined and the relationships between various parameters are explored.
Article
Mechanics
Qian Mao, Jiazhen Zhao, Yingzheng Liu, Hyung Jin Sung
Summary: The hydrodynamic mechanism of drag reduction by a rotationally oscillating cylinder with a flexible filament was explored using the penalty immersed boundary method. The study found that drag reduction is achieved through different mechanisms depending on the oscillation mode.
Article
Chemistry, Multidisciplinary
Seunggyu Kim, Hyeono Nam, Beomseok Cha, Jinsoo Park, Hyung Jin Sung, Jessie S. Jeon
Summary: The cytotoxic response of natural killer (NK) cells in a microreactor to surface acoustic waves (SAWs) is investigated. Results show that SAWs do not damage suspended NK cells, and can increase intracellular Ca2+ concentrations and enhance cell-mediated cytotoxicity.
Article
Engineering, Multidisciplinary
Jun-Duo Zhang, Hyung Jin Sung, Wei-Xi Huang
Summary: In this study, the hydrodynamic interaction between the large crescent dorsal fin and caudal fin in tuna was numerically explored. The presence of the dorsal fin substantially enhanced the thrust on the caudal fin, and a constructive interaction between the leading-edge vortex on the caudal fin and the vortices shed from the dorsal fin was identified. The flapping phase of the caudal fin and the Strouhal number had an influence on the dorsal fin-caudal fin interaction, while the Reynolds number did not have a substantial effect.
BIOINSPIRATION & BIOMIMETICS
(2022)
Article
Mechanics
Qian Mao, Jiazhen Zhao, Yingzheng Liu, Hyung Jin Sung
Summary: This study investigates the hydrodynamic mechanism of drag reduction by a flexible hairy coating through simulations and experimental data comparison, revealing the importance of flexible hairy coatings in drag reduction and the effects of different parts of the coating on drag reduction.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Min Yoon, Hyung Jin Sung
Summary: This study explores wall-attached structures in a drag-reduced turbulent channel flow and examines their influence on drag reduction. The results show that the population density of wall-attached structures decreases and the friction density reduces with streamwise slip, leading to an overall drag reduction.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Mechanics
Qian Mao, Yingzheng Liu, Hyung Jin Sung
Summary: This study investigated the hydrodynamic mechanism of drag reduction by flapping a flexible filament behind a stationary cylinder using the penalty immersed boundary method. The effects of filament parameters on drag reduction were examined, and three distinct flapping modes were observed. The oscillation and undulation modes were found to be more beneficial for drag reduction than the vortex-dominated mode.
Article
Environmental Sciences
Younghun Kim, Dongho Shin, Kee-Jung Hong, Gunhee Lee, Sang Bok Kim, Inyong Park, Bangwoo Han, Jungho Hwang
Summary: This study established a theoretical model to estimate the performance of various indoor air quality management methods for controlling indoor PM2.5 concentrations and energy consumption. The model was verified through comparative experiments. The study identified efficient energy-saving PM2.5 management scenarios using different IAQ management methods based on the annual life patterns of residents in South Korea. The results showed that energy consumption could be significantly reduced by applying natural ventilation in certain seasons and mechanical ventilation in others.
Article
Construction & Building Technology
Younghun Kim, Dongho Shin, Kee-Jung Hong, Gunhee Lee, Sang Bok Kim, Inyong Park, Hak-Joon Kim, Yong-Jin Kim, Bangwoo Han, Jungho Hwang
Summary: This study predicts and experiments on the control of PM2.5 during cooking in apartments, and predicts indoor PM2.5 concentrations under different IAQ management methods. By comparing experimental results, an effective PM2.5 control scheme is proposed.
Article
Mechanics
Qian Mao, Yingzheng Liu, Hyung Jin Sung
Summary: The hydrodynamic mechanism of drag reduction by flapping flexible filaments behind a cylinder was investigated using the penalty immersed boundary method. The effects of phase difference, attachment height, and flapping amplitude on drag reduction were studied. Flapping filaments weaken vortex shedding through destructive interaction, with out-of-phase filaments showing better drag reduction than in-phase filaments. Minimum drag is achieved at appropriate attachment height and flapping amplitude to avoid filament collision and weaken shear-layer-filament interaction. The clapping filaments are more effective than snaking filaments. The total drag decreases with increasing Reynolds number, transitioning from 2S mode to P + S mode wake pattern.
Article
Mechanics
Guo-Zhen Ma, Chun-Xiao Xu, Hyung Jin Sung, Wei-Xi Huang
Summary: Direct numerical simulations (DNSs) were conducted to investigate the effects of roughness on statistical properties and large-scale coherent structures in turbulent channel flow over three-dimensional sinusoidal rough walls. The study examined the similarities in mean streamwise velocity and Reynolds stresses in the outer layer by varying the roughness Reynolds number and the ratio of roughness height to the half-channel height. Spectral analysis and scale-energy path display were used to explore the energy transfer mechanism of turbulent motions with different sized roughness elements. The results showed that increasing roughness Reynolds number led to a downward shift of the mean velocity profile and decreased intensity of turbulent Reynolds stresses.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Mechanics
Qian Mao, Yingzheng Liu, Hyung Jin Sung
Summary: The flow-induced snap-through dynamics of a buckled flexible filament were studied by using the penalty immersed boundary method. The effects of filament length, bending rigidity, and Reynolds number on the mode transition were systematically investigated. Three different modes were observed when these parameters were varied: equilibrium mode, streamwise oscillation mode, and snap-through oscillation mode. The increase in transverse fluid force induced the snap-through oscillation mode, while a vortex-induced vibration and a self-excited vibration occurred in the streamwise oscillation mode and snap-through oscillation mode respectively.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Biochemical Research Methods
Hyeono Nam, Jong-Eun Park, Waqas Waheed, Anas Alazzam, Hyung Jin Sung, Jessie S. Jeon
Summary: Traveling surface acoustic waves (SAWs) were used for the lysis of cancer cells without any chemical reagents, followed by Raman spectrum profiling to explore detailed cell-derived data. Mechanical cell lysis was achieved using polystyrene microparticles (PSMPs) and the Raman signals from the lysed cells were enhanced by gold nanoparticles (AuNPs) through nanogaps formed by the AuNPs. The lysis efficiency was evaluated by varying the size and concentration of the PSMPs.
