Article
Mechanics
Biao Shen, Takeshi Hamazaki, Kohei Kamiya, Sumitomo Hidaka, Koji Takahashi, Yasuyuki Takata, Junji Nunomura, Akihiro Fukatsu, Yoichiro Betsuki
Summary: Combining porous texturing with surface wettability engineering significantly enhances saturated pool boiling of ethanol, with over-twofold increases in heat transfer coefficient recorded on the textured surfaces compared to plain smooth surfaces. The boiling incipience point on porous surfaces shows a dependence on the initial wetting state, and applying amphiphobic coatings creates a biphilic pattern for efficient nucleate boiling with consistently low superheats. The reduction of minimum superheat at boiling onset by more than 80% hints at a nanobubble-related mechanism less affected by incondensable gas compared to the classic vapor-trapping-cavity model.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Polymer Science
Cassia Lux, Thomas Tilger, Ramsia Geisler, Olaf Soltwedel, Regine von Klitzing
Summary: The study investigates tailored functionalization of cellulose based papers by preparing polyelectrolyte multilayers (PEMs), revealing that different polycations lead to PEMs with different surface topographies, and these PEMs exhibit high water uptake in humid environments.
Article
Materials Science, Multidisciplinary
Jongkyeong Lim, Jeonghyeon Hwang, Joonwon Kim
Summary: This study demonstrates the rapid and accurate manufacture of 3D vascular replicas with a smooth inner surface using wax-coated molds, reducing processing time significantly.
ADVANCED MATERIALS TECHNOLOGIES
(2021)
Article
Engineering, Environmental
Karuppusamy Indira, Arivalagan Pugazhendhi, M. Rajasekar, Nallaiyan Rajendran, Arunachalam Chinnathambi, Sulaiman Ali Alharbi, Nguyen Chi Thanh, Kathirvel Brindhadevi
Summary: Niobium ions were successfully incorporated into highly ordered TiO2 nanotube arrays for the first time, showing improved charge separation efficiency and potential as a promising photocatalyst for the degradation of organic pollutants.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Peiliu Li, Fei Zhan, Lei Wang
Summary: This study investigates the motion of droplets on anisotropic surfaces through experiments, theoretical models, and energy balance analysis. The research finds that the direction of droplet rebound on an anisotropic surface can be switched by designing the initial impacting velocity, and the motion of the droplet changes with an increase in impacting height.
Article
Biochemical Research Methods
Matthias Hermann, Prashant Agrawal, Chang Liu, J. C. Yves LeBlanc, Thomas R. Covey, Richard D. Oleschuk
Summary: The rapid calibration chip (RCC) uses the wetting behavior of hydrophilic/hydrophobic patterns to confine droplets and obtain a calibration curve. It doesn't require advanced equipment and can form multiple droplet series quickly. Evaluation of its performance allows for determining liquid volumes.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2022)
Article
Materials Science, Multidisciplinary
Abba Abdulhamid Abubakar, Bekir Sami Yilbas, Mubarak Yakubu, Hussain Al-Qahtani, Ghassan Hassan, Johnny Ebaika Adukwu
Summary: This study investigates the impact mechanisms of water droplets on hydrophobized micro-post array surfaces, exploring the influence of micro-post array spacing on droplet behavior. Results show that increasing micro-post array spacing reduces maximum spreading diameter and creates a pinning effect on droplet kinetic energy. Flow circulation occurs inside the droplet during spreading, while opposing flow takes place during retraction, leading to a stagnation zone in the central region of the droplet. Additionally, impacting droplets help mitigate dust from micro-post array surfaces and increasing droplet Weber number increases the area of dust mitigated.
Article
Automation & Control Systems
Diana Marisa Monteiro Faria, Bruno Alexandre Pacheco de Castro Henriques, Anne Caroline Bernardes De Souza, Filipe Samuel Correia Pereira da Silva, Oscar Samuel Novais Carvalho
Summary: This study explored a new design for implants surface functionalization through the manufacture of 45S5 Bioglass-coated zirconia structured surfaces using a hybrid laser technique. The results showed promising outcomes in terms of morphology, bioactivity preservation, surface wettability, friction performance, and mechanical resistance of zirconia. The synergistic effect of physical and chemical changes on the zirconia surface with advanced laser methods seems to be a promising approach for producing implants with enhanced bioactivity.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Chung-Te Huang, Ching-Wen Lo, Ming-Chang Lu
Summary: This study developed a superhydrophobic surface with a double-reentrant groove (DRG) array, which can suppress the Leidenfrost effect and reduce the contact time of droplets impacting a solid surface at high temperatures.
Article
Environmental Sciences
Osman Karatum, Stephen A. Steiner iii, Desiree L. Plata
Summary: This study explores the preparation of CO2-switchable aerogel surfaces using drop casting, dip coating, and physical vapor deposition techniques. The experiments showed that the surface coating of TBPA onto aerogel blankets was partially successful under certain conditions, but the post-aerogel modification strategies yielded poor reproducibility. The success rate of coating onto aerogel surfaces was 6.25%, 11.7%, and 18% for PVD, drop casting, and dip coating, respectively.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Mechanics
Kai Sun, Lingyun Shu, Feifei Jia, Zhe Li, Tianyou Wang
Summary: Vibration on superhydrophobic surfaces is an effective method for removing droplets. This study experimentally investigated the dynamics of droplets on vibrating superhydrophobic surfaces and established a theoretical model to explain the physics behind droplet detachment caused by vibration. It was found that different droplet oscillation patterns exist and the critical condition for droplet detachment depends on the droplet energy compared to the surface adhesion energy. The study also revealed the impact of vibration frequency and amplitude on droplet detachment time.
Article
Energy & Fuels
Jeevan Kumar Reddy Modigunta, Keun No Park, Su Cheol Shin, G. Murali, Udhayakumar Hari Haran, Jeongmin Kim, Jemin Yeon, Seongmin Park, Hyunju Jang, Young Ho Park, Ji-Young Noh, Jung-Hyurk Lim, Jihoon Lee, Seung Jun Lee, Kyung-Min Kim, Insik In
Summary: In this study, a waterborne spontaneous coating of CAPOSS on hydrophobic substrates was achieved, resulting in a nano-scale level coating with robust adhesion, enhanced hydrophilicity, electrolyte wettability, mechanical strength, and thermal stability. The CA-POSS coated PE separator showed improved performance in lithium ion batteries.
JOURNAL OF ENERGY STORAGE
(2023)
Article
Chemistry, Multidisciplinary
Annika Morgenstern, Rico Thomas, Apoorva Sharma, Marcus Weber, Oleksandr Selyshchev, Ilya Milekhin, Doreen Dentel, Sibylle Gemming, Christoph Tegenkamp, Dietrich R. T. Zahn, Michael Mehring, Georgeta Salvan
Summary: Bismuth compounds have attracted growing interest due to their potential applications in catalysis, medicine, and electronics. However, the low solubility of bismuth oxido precursors hampers their further development. In this study, the solubilization of bismuth oxido clusters was achieved by introducing an amino carboxylate as a functional group. The exchange of nitrates by amino carboxylates was confirmed by various spectroscopic techniques. The solubility of the clusters in different solvents and their growth mode on gold surfaces were investigated using microscopy and spectroscopy.
Article
Thermodynamics
Xin Wang, Bo Xu, Qiusheng Liu, Yang Yang, Zhenqian Chen
Summary: Recently developed micro- or nano-structured surfaces have been used to enhance condensation heat transfer, water harvesting, and self-cleaning. However, condensate flooding at large subcoolings leads to decreased heat transfer efficiency. Superhydrophobic surfaces with micropillar and nanopillar structures have been proposed to improve heat transfer in such conditions. Experiments have shown that droplet dynamics and heat transfer performance are influenced by micropillar spacing and surface subcooling. Additionally, a microscopic modeling approach using the mesoscopic lattice Boltzmann method has been utilized to study condensation heat transfer on these surfaces. The results demonstrate that micropillared surfaces exhibit smaller droplet size distribution compared to nanostructured surfaces, but the heat transfer coefficient decreases with increased micropillar spacing. In high subcooling conditions, the S10R30 micropillar arrays have shown a 26.4% enhancement in heat transfer coefficient compared to hydrophobic nanostructured surfaces, due to the reduction in thermal resistance caused by the liquid film height being on the same order of magnitude as the micropillars.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Review
Materials Science, Multidisciplinary
Nisa Nashrah, Rosy Amalia Kurnia Putri, Early Zahwa Alharissa, Wail Al Zoubi, Young Gun Ko
Summary: Hybrid organic-inorganic (HOI) materials have gained significant attention for their combination of unique properties from organic and inorganic compounds. This review focuses on the formation and electrochemical performance of HOI materials, which can be controlled through microstructural design, and summarizes recent strategies for preparing HOI materials on metallic surfaces. The corresponding electrochemical behaviors for both short and long term exposures are also outlined.
Article
Biotechnology & Applied Microbiology
Nikolaj Kofoed Mandsberg, Wenting Liao, Yoshihiro Alexander Yamanouchi, Anja Boisen, Hirotaka Ejima
Summary: The study shows that metal-phenolic networks can successfully encapsulate green algae, delaying cell proliferation, adsorption, and enhancing harvest efficiency, providing new possibilities for surface engineering applications of green algae.
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2022)
Article
Nanoscience & Nanotechnology
Alireza Assar, Filipe Martinho, Jes Larsen, Nishant Saini, Denver Shearer, Marcos V. Moro, Fredrik Stulen, Sigbjorn Grini, Sara Engberg, Eugen Stamate, Jorgen Schou, Lasse Vines, Stela Canulescu, Charlotte Platzer-Bjorkman, Ole Hansen
Summary: Multijunction solar cells in a tandem configuration using crystalline silicon as the bottom cell can reduce electricity costs. However, only a limited number of top and bottom cell architectures are compatible for direct integration on silicon. By using polySi/SiOx passivating contacts, degradation can be minimized and the lifetime of the bottom cell can be increased. Applying this concept to low-cost top cell chalcogenides, the efficiency and resilience of the tandem solar cells can be improved.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Ceramics
Sara Engberg, Mungunshagai Gansukh, Filipe Martinho, Eugen Stamate, Ole Hansen, Jorgen Schou, Stela Canulescu
Summary: This study successfully incorporated silver into the CZTS lattice using cation substitution, which reduced the disorder and band tailing effects. The best efficiency was achieved with 13% Ag/(Ag+Cu), reaching 4.9%. In addition, silver incorporation also improved grain growth and increased the band gap.
CERAMICS INTERNATIONAL
(2022)
Article
Mechanics
V. L. Okulov, B. R. Sharifullin, N. Okulova, J. Kafka, R. Taboryski, J. N. Sorensen, I. Naumov
Summary: Experiments were conducted using a water-filled elongated cup of a kitchen scale with a rotating disk with micro- and nano-roughness. The results showed that certain nanostructures led to significant growth of vortices while other roughnesses did not impact the flow structure. These findings are important for evaluating the efficiency of surfaces with nanoscale roughnesses and have potential applications in enhancing mixing in chemical and bio-reactors.
Article
Engineering, Multidisciplinary
Benny Guralnik, Ole Hansen, Andreas R. Stilling-Andersen, Soren E. Hansen, Kasper A. Borup, Besira M. Mihiretie, Braulio Beltran-Pitarch, Henrik H. Henrichsen, Rong Lin, Lior Shiv, Bo B. Iversen, Peter F. Nielsen, Dirch H. Petersen
Summary: Micro four-point probing is an electrical metrology technique that accurately measures the electrical and electromagnetic properties of charge carriers at the micrometer scale. In this study, we propose and demonstrate a new application of micro four-point probe for quantifying the thermoelectric properties of a sample. We show that the voltage drop across the sensing electrodes is proportional to the ratio of the Seebeck coefficient to thermal conductivity, and our measurements on various semiconductor materials exhibit high accuracy and precision, indicating a novel in-situ metrology of thermoelectric properties at the micrometer scale.
MEASUREMENT SCIENCE AND TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Ganapathi Prabhu Sai Balasubramanian, Elizaveta Lebedkina, Nebile Isik Goktas, Jakob Birkedal Wagner, Ole Hansen, Ray LaPierre, Elizaveta Semenova, Kristian Molhave, Marco Beleggia, Elisabetta Maria Fiordaliso
Summary: Off-axis electron holography was used to observe remote doping in GaAs nanowires during in situ annealing in a transmission electron microscope. Dynamic changes in electrostatic potential caused by carbon dopant diffusion upon annealing were measured, and the electrostatic potential profiles were extracted from GaAs nanowires with radial p-p+ core-shell junctions. The experiment showed that the built-in potentials remained nearly constant and the depletion layer widths slightly increased, contrary to the predictions made in the absence of remote doping. A depression in the potential profile of the core upon annealing was also observed, which was attributed to carbon diffusion from the shell to the core through the nanowire sidewalls.
Article
Chemistry, Multidisciplinary
Nikolaj K. Mandsberg, Anna Shneidman, Kaare H. Jensen, Rafael Taboryski, Line H. Nielsen, Joanna Aizenberg, Anja Boisen
Summary: A method of producing droplet arrays with gradients in droplet height by dip-coating uniformly patterned biphilic substrates in acceleration-mode has been developed, allowing for the adjustment of droplet characteristics and demonstrating promising applications in experiments.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Braulio Beltran-Pitarch, Benny Guralnik, Neetu Lamba, Andreas R. Stilling-Andersen, Lars Norregaard, Torben M. Hansen, Ole Hansen, Nini Pryds, Peter F. Nielsen, Dirch H. Petersen
Summary: In order to develop materials with higher thermoelectric efficiency, a new method based on micro four-point probe (M4PP) was developed to determine the thermal diffusivity of a bulk material using the phase delay of the second harmonic voltage. The method was tested on two relevant thermoelectric materials, skutterudite and bismuth telluride, and showed good agreement with independent estimates. The M4PP method also demonstrated the ability to characterize materials with nonuniform and erratic electrical resistivity, such as bismuth telluride.
MATERIALS TODAY PHYSICS
(2023)
Article
Optics
Arnhold Simonsen, Gyeong Cheol Park, Thor Ersted Ansbaek, Ole Hansen, Kresten Yvind
Summary: In this letter, we introduce a 2D mirror design that offers a large optical bandwidth and high reflection. This design is also more rigid than 1D mirrors. We specifically study the impact of rounded corners of rectangles during the transfer from CAD to the wafer using lithography and etching.
Article
Plant Sciences
Marc Fradera-Soler, Jozef Mravec, Alexander Schulz, Rafael Taboryski, Bodil Jorgensen, Olwen M. Grace
Summary: Hydathode-mediated foliar water uptake (FWU) has been observed in the leaf-succulent genus Crassula, a diverse group of plants in southern Africa. This FWU ability is not restricted to arid environments and is independent of leaf surface wettability. It is an adaptation that allows Crassula species to harvest moisture from the atmosphere.
PLANT CELL AND ENVIRONMENT
(2023)
Article
Engineering, Manufacturing
Federico Cantoni, Daniel Maher, Eugenia Bosler, Stefan Kuhne, Laurent Barbe, Dirk Oberschmidt, Christophe Marquette, Rafael Taboryski, Maria Tenje, Ada- Ioana Bunea
Summary: Since its introduction in the 1980s, 3D printing has developed as a versatile and reliable tool with applications in different fields. Among these, two-photon polymerization is considered one of the most promising technologies due to its ability to achieve high precision printing down to submicron scale and free-form structure design. Recent advancements in faster laser scanning strategies and new photoresists have further enhanced this technology, leading to a wider range of applications. This study aims to provide an overview of the technology capability by comparing three commercial systems in a round-robin test.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Electrical & Electronic
M. Serra Gonzalez, M. Keil, R. Deshpande, S. Kadkhodazadeh, N. Okulova, R. J. Taboryski
Summary: In this work, a complete process flow combining resolution enhancement techniques (RETs) and roll-to-roll extrusion coating (R2R-EC) is proposed to produce large-scale nanopillar arrays. The optimized lithographic parameters and process enable the successful replication of hexagonal and rectangular arrays, which show improved solar absorption efficiency and heat radiation blocking after metallization.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
(2023)
Proceedings Paper
Acoustics
Stine Lovholt Grue Pedersen, Andreas Spandet Havreland, Ole Hansen, Erik Vilain Thomsen
Summary: This article introduces the importance of the resonance frequency of ultrasound transducers in the field of ultrasound, and proposes a new expression for deriving the resonance frequency in immersion. By considering the influence of the immersion medium, an approximation of the radiation impedance is obtained using the Taylor expansion, and the use of the Fade approximant is suggested for higher precision at smaller aspect ratios.
2022 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IEEE IUS)
(2022)
Article
Chemistry, Physical
Rasmus Nielsen, Tomas H. Youngman, Hadeel Moustafa, Sergiu Levcenco, Hannes Hempel, Andrea Crovetto, Thomas Olsen, Ole Hansen, Ib Chorkendorff, Thomas Unold, Peter C. K. Vesborg
Summary: Research on selenium solar cells is gaining momentum again due to its potential for integration with existing photovoltaic technology and its low cost. However, there are still voltage deficiencies in single-junction selenium devices, calling for further study on the material properties.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
