Article
Physics, Applied
Hong Hu, Suo Zhao, Wenshuo Wang, Yuqi Zhang, Yu Fu, Zijian Zheng
Summary: The study derived a simple analytical formula based on classic order statistics to predict the interfacial binding energy between rough surfaces, highlighting the strong length scale dependence of adhesion. Comparison with experimental results showed that the formula holds its accuracy, particularly for the Derjaguin-Muller-Toporov adhesion case.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Man Wang, Yi Wan, Gongming Xin
Summary: In this study, the influence of vibration on the evaporation and boiling performance of water nanofilm on rough surfaces was investigated using molecular dynamics method. The results showed that vibration suppressed the atomization of water nanofilm, and the atomization modes varied with the amplitude and frequency of the vibration. For rough surfaces, the weakening of vibration-induced evaporation and boiling performance of water nanofilm was attributed to the reduction of surface hydrophilicity.
APPLIED SURFACE SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Tobias Materzok, Danna De Boer, Stanislav Gorb, Florian Mueller-Plathe
Summary: A particle-based mesoscale gecko spatula model is developed to bridge atomistic simulations and mesoscale simulations. The model successfully reproduces experimental pull-off forces and reveals the correlation between spatula detachment and surface roughness.
Article
Chemistry, Multidisciplinary
Qun Cao, Zirui Li, Zheng Cui
Summary: This paper investigates the effect of surface roughness on liquid-vapor phase change heat transfer and its microscopic mechanism using molecular dynamics simulation. The results show that pits on rough surfaces provide stable nucleation sites for bubbles, and as the surface roughness increases, bubble generation, merging, and growth are advanced.
Article
Chemistry, Physical
Srinivas Mushnoori, Jack A. Logan, Alexei V. Tkachenko, Meenakshi Dutt
Summary: This study uses Brownian dynamics to investigate self-assembly in a hybrid system of isotropic particles and anisotropic building blocks. By simulating annealing and analyzing structure characteristics, it is found that the resultant structures exhibit different symmetries and degrees of order for different size ratios.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Simen Ringdahl, Senbo Xiao, Jianying He, Zhiliang Zhang
Summary: In this paper, the role of surface roughness in ice adhesion strength was investigated using molecular dynamics simulations and machine learning. It was found that a thin quasi-liquid layer on rough surfaces reduced the ice adhesion strength, and support vector machines emerged as the best classification tool in machine learning for this application. The study highlights the potential of using machine learning in anti-icing surface design and provides a better understanding of the intrinsic ice adhesion on rough surfaces.
Article
Chemistry, Physical
Dan Su, Lei Zhang, Jianying Guo, Shengyu Liu, Bao Li
Summary: This study employed molecular dynamics simulations to clarify the mechanism of adsorption and accumulation of gas on rough surfaces during flotation, revealing that van der Waals force plays a leading role throughout the entire adsorption process. The findings contribute to a better understanding of the gas-liquid-solid interaction mechanism in the flotation process.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Mechanics
Yanling Chen, Liang Guo, Wanchen Sun, Ningning Cai, Yuying Yan
Summary: This study investigates the effects of surface wettability and rough structure on the wetting behavior of fuel droplets after hitting the walls using molecular dynamics method. The results show that a decrease in the solid-liquid interaction coefficient leads to an increase in the static contact angle and rough surface structures inhibit the spreading of the droplets. Additionally, specific boss-shaped structures enhance the surface oleophobicity.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Chemistry, Physical
Chang Guo, Can Ji, Yalong Kong, Zhigang Liu, Lin Guo, Yawei Yang
Summary: In this study, a modified molecular dynamics simulation was used to investigate bubble nucleation on rough nanostructured substrates with different liquid-solid interactions. The results show that as the contact angle decreases, the nucleation rate increases due to more thermal energy being transferred to the liquid on better-wetting surfaces. The rough profiles of the substrate provide nanogrooves that enhance initial bubble nucleation and improve thermal energy transfer efficiency. Additionally, atomic energies are calculated and adopted to explain the formation of bubble nuclei on various wetting substrates. The simulation results are expected to guide surface design in state-of-the-art thermal management systems, such as surface wettability and nanoscale surface patterns.
Article
Chemistry, Multidisciplinary
Yuming Yin, Lingling Zhao, Shangchao Lin
Summary: Using molecular dynamics simulations, this study investigates the wetting characteristics of CO2 on smooth and rough surfaces. The results show that the contact angle of CO2 droplets decreases on smooth surfaces with increasing CO2-solid interaction energy, while it increases on rough surfaces with higher surface roughness. The study also uncovers the capillary drying-out phenomenon of CO2 molecules at the three-phase contact line of the droplets, which has been overlooked in previous theoretical studies.
Article
Engineering, Mechanical
Jianjun Bian, Lucia Nicola
Summary: Results from molecular dynamics simulations show that covering the rough copper surface with a wrinkled graphene layer is the best solution for reducing friction.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Chemistry, Multidisciplinary
Fei Zeng, Lin-Li Tang, Juan Liao, Man-Hua Ding, Guang-Chuan Ou
Summary: The sandwich, macrocycle, and box supramolecular assemblies were synthesized from the reaction of 1,8-bis(4-pyridylethynyl)anthracene 1 with various phenolic compounds; investigation of their crystal structures indicated that the distance between two oxygen atoms in a hydrogen bonding donor is crucial for the formation of these supramolecular assemblies.
Article
Engineering, Mechanical
Chongpu Zhai, Shuwen Zhang, Hui Ji, Deheng Wei, Hengxu Song, Kaiyuan Liu, Minglong Xu
Summary: This study quantifies the impact of surface roughness on interfacial flexoelectricity during normal compression and oscillation. Through examining 3D-printed surfaces with different roughness features, the researchers found that the flexoelectric charge follows a power-law relationship with the compression load, and the exponent is positively correlated with the fractal dimension. Contact analyses reveal that the flexoelectric charge concentrates on larger microcontacts as compression continues, and rougher surfaces show less heterogeneity in flexoelectric polarizations. This study provides experimental measurements and explanations for interfacial flexoelectricity, highlighting its connection to surface structures and suggesting new approaches for contact evaluation and flexoelectricity enhancement.
EXTREME MECHANICS LETTERS
(2023)
Article
Polymer Science
Takuya Ohzono, Emiko Koyama
Summary: In this study, a photosensitive nematic main-chain liquid crystal elastomer (LCE) with switchable adhesion properties on rough surfaces was demonstrated. The LCE can deform to adapt to rough surfaces under light, resulting in enhanced adhesion ability. By proper light irradiation, the LCE exhibits rubber elasticity, leading to reduced adhesion on rough surfaces. This LCE with switchable elasticity is of great significance for treating objects with rough surfaces.
Review
Mechanics
Daniel Chung, Nicholas Hutchins, Michael P. Schultz, Karen A. Flack
Summary: Reliable full-scale prediction of drag due to rough wall-bounded turbulent fluid flow remains a challenge, with at least 10% uncertainty. Recent advances have lowered barriers and are beginning to impact other multiphysical areas, promising increased predictive reliability.
ANNUAL REVIEW OF FLUID MECHANICS, VOL 53
(2021)
Article
Materials Science, Biomaterials
Lap Tak Hung, Stephanie Hiu Ling Poon, Wing Huen Yan, Rebecca Lace, Liangyu Zhou, Jasper Ka Wai Wong, Rachel L. Williams, Kendrick Co Shih, Ho Cheung Shum, Yau Kei Chan
Summary: A strategy using a biocompatible polymer-based liquid-liquid interface has been developed for the rapid fabrication of scaffold-free corneal tissue constructs. The formed constructs exhibit essential physiological markers, preserved viability and proliferative ability, and can repair corneal epithelial wounds in vitro.
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2022)
Article
Multidisciplinary Sciences
Yi Pan, Zhenyu Yang, Chang Li, Sammer Ul Hassan, Ho Cheung Shum
Summary: The healthy functioning of plants' vasculature relies on their ability to respond to environmental changes. Inspired by the way plants respond to environmental stimuli, researchers have developed a transformable microfluidic device that can respond to temperature, humidity, and light irradiance. By incorporating stimuli-responsive materials and a foldable geometry, this device can undergo responsive movements similar to origami transformations. It has been named TransfOrigami microfluidics (TOM) to emphasize its transformation and origami structure. TOM can be used as an environmentally adaptive photomicroreactor, which senses environmental stimuli and utilizes morphological transformation to enhance photosynthetic conversion. This concept of a morphable microsystem has the potential to be applied in various fields that require responsiveness between the environment and devices, such as dynamic artificial vascular networks and shape-adaptive flexible electronics.
Article
Chemistry, Multidisciplinary
Sai Zhao, Jun-Yan Zhang, Yuchen Fu, Shipei Zhu, Ho Cheung Shum, Xubo Liu, Zhaoyu Wang, Ruquan Ye, Ben Zhong Tang, Thomas P. Russell, Yu Chai
Summary: Ferrofluids can form structures and maintain their shape in a magnetic field, exhibiting reconfigurability and structural stability. By manipulating the external magnetic field, the shape of ferrofluids can be remotely written and erased repeatedly. This study provides a new method for manipulating ferrofluids and opens possibilities for the fabrication of all-liquid devices.
Article
Chemistry, Applied
Yijie Wang, Xiufeng Li, Ting Li, Yang Wang, Jie Jiang, Xuhui Zhang, Jing Huang, Bihua Xia, Ho Cheung Shum, Zhenzhong Yang, Weifu Dong
Summary: A chemical approach is used to fabricate particles by combining a water-insoluble plant protein and a hydrophilic polysaccharide, resulting in adjustable interfacial wettability and improved absorption kinetics for emulsions.
FOOD HYDROCOLLOIDS
(2023)
Article
Chemistry, Multidisciplinary
Wei Guo, Danyang Ji, Andrew B. Kinghorn, Feipeng Chen, Yi Pan, Xiufeng Li, Qingchuan Li, Wilhelm T. S. Huck, Chun Kit Kwok, Ho Cheung Shum
Summary: RNA encodes interactions to modulate the properties of biomolecular condensates, and rG4s formed by guanine-rich sequences can trigger the formation of these condensates. The mechanisms by which rG4 motifs modulate phase transitions and material properties of condensates are unclear.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Biochemical Research Methods
Fang Wang, Chang Li, Ruotong Zhang, Yuan Liu, Haisong Lin, Lang Nan, Muhammad Ajmal Khan, Yang Xiao, Ho Cheung Shum, Hui Deng
Summary: Cold atmospheric plasma chip enables targeted and multi-dosage treatment of multiple cell lines in a single session. This innovative approach provides a new tool for investigating the mechanisms of plasma-induced anticancer effects and guiding clinical applications.
Article
Chemistry, Multidisciplinary
Shi Yang, Han Yu, Xiuli Xu, Ting Yang, Yue Wei, Rui Zan, Xiaonong Zhang, Qingming Ma, Ho Cheung Shum, Yang Song
Summary: This article presents the synthesis of a peptide-based RNA sensor by connecting aggregation-induced emission luminogen (AIEgen) tetraphenylethylene (TPE) to tandem peptide repeats of (RRASL)n (n = 1, 2, 3). The conjugation of TPE promotes liquid-liquid phase separation of the peptide repeats, with significantly decreased minimum coacervation concentration (MCC) compared to the untagged counterparts. Furthermore, the luminescence of TPE-(RRASL)n is greatly enhanced with increasing RNA concentration, attributed to the constricted rotation of the TPE moiety within the droplet phase formed by peptide/RNA coacervates. In addition, TPE-(RRASL)n can efficiently penetrate human gallbladder carcinoma cells, translocate into the nucleus, and colocalize with intracellular RNA, highlighting its potential as a droplet-based biosensor for intracellular RNA imaging.
Article
Chemistry, Multidisciplinary
Chang Li, Yafeng Yu, Huizeng Li, Haisong Lin, Huanqing Cui, Yi Pan, Ruotong Zhang, Yanlin Song, Ho Cheung Shum
Summary: The heterogeneous self-assembly of a single type of nanoparticle is achieved by quickly evaporating a colloid-poly(ethylene glycol) (PEG) droplet, facilitated by the spatial confinement induced by a skin layer. This approach allows for the formation of face-centered-cubic (FCC) lattices with different plane orientations, generating binary bandgaps and structural colors. The self-assembly of nanoparticles can be regulated by adjusting the PEG concentration, and the method is applicable to various droplet shapes, substrates, and nanoparticle types.
Article
Chemistry, Multidisciplinary
Yanting Shen, Yuan Liu, Janine K. Nunes, Chenmin Wang, Miao Xu, Michael K. T. To, Howard A. Stone, Ho Cheung Shum
Summary: Injectable fibro-gel, a water-filled network of entangled hydrogel microfibers, has shown great potential in tissue engineering and regenerative medicine due to its injectability, tailorable physicochemical properties, and controlled drug release profiles. Preliminary in vivo tests on a mice excision skin model have demonstrated that the fibro-gel promotes faster wound healing and new tissue regeneration compared to a commercial gel. Moreover, the release of distinct drugs at different rates using a two-layer fibro-gel model further enhances wound healing efficiency.
ADVANCED MATERIALS
(2023)
Article
Multidisciplinary Sciences
Zehao Pan, Janine K. Nunes, Camille Duprat, Ho Cheung Shum, Howard A. Stone
Summary: When a suspension of particles passes through a constriction, the particle volume fraction either decreases or remains unchanged. However, an entangled fiber suspension can increase its volume fraction by over 10 times after passing through a constriction. This increase is attributed to the entanglements among the fibers, which allow the network to move faster than the liquid. This finding provides a new strategy to control soft material properties during delivery processes in healthcare, 3D printing, and material repair.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Feipeng Chen, Xiufeng Li, Yafeng Yu, Qingchuan Li, Haisong Lin, Lizhi Xu, Ho Cheung Shum
Summary: The authors present a one-step fabrication method based on aqueous phase separation to construct two-aqueous-phase gels with multiple phases. These gels exhibit enhanced interfacial mechanics and can be conveniently constructed with programmable structures and tunable properties. The versatility of this approach is demonstrated by mimicking various biological architecture features at different length scales.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Yi Pan, Chang Li, Xiaoyu Hou, Zhenyu Yang, Mingzhu Li, Ho Cheung Shum
Summary: The challenge of achieving individually and independently programmable stimuli-responsive color pixels in color-changing soft materials and devices has been addressed by designing a morphable concavity array on a two-dimensional photonic crystal elastomer. By using multichannel microfluidics, the colors of each concavity can be switched controllably, enabling dynamic display for applications such as anti-counterfeiting and encryption.
Review
Chemistry, Multidisciplinary
Yan Zhan, Chang Li, Zhigang Che, Ho Cheung Shum, Xiaotian Hu, Huizeng Li
Summary: Benefiting from their superior photophysical properties and low-cost crystalline substances, perovskites have emerged as competitive photoactive semiconductors for optoelectronic devices. Photon management is crucial for perovskites due to their direct band gap and high refractive index. Photonic structures with periodic features offer efficient means to manage light through the interaction between media and photons. This review discusses strategies of photon management in perovskite optoelectronics and summarizes the design and implementation progress of photonic elements for high-index perovskites. Proposals and guidelines for high-performance multifunctional perovskite optoelectronics are also provided.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Chemistry, Physical
Niki Abbasi, Janine K. Nunes, Zehao Pan, Tejas Dethe, Ho Cheung Shum, Andrej Kosmrlj, Howard A. Stone
Summary: Liquid-liquid phase separation induced by co-flow of a nonequilibrated aqueous two-phase system within a planar flow-focusing microfluidic device is experimentally demonstrated. Invasion fronts from the outer stream are formed along the top and bottom walls of the microfluidic device, which merge as the system reaches steady-state. The formation and growth of the invasion fronts are driven by Marangoni flow induced by the polymer concentration gradient along the width of the channel during phase separation.
Article
Chemistry, Multidisciplinary
Ben H. Skopic, Sean R. Koebley, Hannes C. Schniepp
Summary: The silk ribbon of recluse spiders has surprising adhesive properties, as its junctions exhibit a self-strengthening mechanism that increases the adhesive strength by 550%. This unique mechanism overcomes the weak peeling failure typically observed in adhesive tapes.
MATERIALS HORIZONS
(2022)
