Article
Engineering, Electrical & Electronic
Mathias Heiduk, Michael J. Wolf, Walter H. Fietz
Summary: This article introduces the High Temperature Superconductor (HTS) CroCo cable concept developed by the Karlsruhe Institute of Technology, as well as the manufacturing process and testing of the fabricated conductor.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Engineering, Electrical & Electronic
Yi Li, Siwei Chen, Mahesh Paidpilli, Rohit Jain, Chirag Goel, Venkat Selvamanickam
Summary: A reel-to-reel scanning Hall-probe microscopy system has been developed to characterize REBCO conductors. This system enables contact-free and non-destructive 2-dimensional imaging of critical current density distribution by mapping the screening-current-induced field of a magnetized conductor. The system overcomes the challenges of measuring weak screening-current-field signals in a strong background field.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Book Review
Multidisciplinary Sciences
Katrin Daehn
Summary: This sentence suggests that an extensive history can provide insights into the various aspects of the abundant metal.
Article
Mechanics
Kaushlendra Dubey, Sanjeev Sanghi, Amit Gupta, Supreet Singh Bahga
Summary: The study investigates the electrokinetic instability (EKI) in microchannel flow with streamwise conductivity gradients, commonly seen during sample stacking in capillary electrophoresis. Through experiments and numerical simulations, the researchers demonstrate how non-uniform electroosmotic flow in areas of varying conductivity can lead to instability above a threshold electric field. The simulations align well with experimental observations, providing insight into the underlying mechanism of the instability.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Multidisciplinary Sciences
Haisong Lin, Wenzhuo Yu, Kiarash A. Sabet, Michael Bogumil, Yichao Zhao, Jacob Hambalek, Shuyu Lin, Sukantha Chandrasekaran, Omai Garner, Dino Di Carlo, Sam Emaminejad
Summary: This study presents a swarm of millimeter-sized magnet robots ('ferrobots') that can handle magnetized sample droplets and deliver nucleic acid amplification tests with precision and reliability. The automated platform demonstrated laboratory-equivalent operations for pooled testing, maximizing testing efficiency. Applied for SARS-CoV-2 virus detection, the results matched those obtained off-chip. The technology is easily manufacturable and distributable, potentially reducing reagent costs and instrumentation cost, making it a promising solution to expand global testing capacity.
Article
Physics, Fluids & Plasmas
Suyash Verma, Arman Hemmati
Summary: Numerical investigation was conducted on the propulsive performance and vortex synchronization of an oscillating foil in combined heaving and pitching motion at different reduced frequencies, phase offsets, and Reynolds numbers. The transition from drag to thrust dominance was observed at specific phase offsets and reduced frequencies, coinciding with transitions in near-wake modes. Changing phase offsets only affected the spatial configuration of vortex structures, while the number of vortices shed in one oscillation period remained constant. These findings suggest that wake topology transitions are not always reliable for understanding propulsive mechanisms in fish swimming or underwater propulsion systems.
Article
Engineering, Mechanical
Talieh Pourashraf, Philip Bonello
Summary: This paper presents the nonlinear and linearised dynamic analyses of three-pad foil air bearing (FAB) rotor systems considering foil detachment and compares the modeling methods of Galerkin Reduction (GR) and Finite Difference (FD). The results are validated and show that GR can accurately predict the nonlinear response.
NONLINEAR DYNAMICS
(2023)
Article
Engineering, Mechanical
Fangcheng Xu, Jianhua Chu, Long Sha
Summary: This paper aims to investigate the effect of top foil sagging on the static performance of air foil thrust bearings. The study considers the nonlinearity of bump foil stiffness and obtains the static characteristics of bearings with different degrees of foil depression. Experimental results match well with theoretical calculations. The findings provide guidance for designing bearings that minimize the influence of sagging on performance.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Chemistry, Physical
N. Reckinger, B. Hackens
Summary: Impurities in copper foil are hindering the scalable production of high-quality graphene by chemical vapor deposition. These impurities have two distinct origins: intrinsic impurities from the manufacturing process of the copper foils, and external silica contamination from the quartz tube. Adequate confinement can solve the problem of external contamination, while electropolishing is particularly effective in reducing the issue of intrinsic impurities.
APPLIED SURFACE SCIENCE
(2023)
Article
Materials Science, Ceramics
Boxi Jin, Xu Huang, Mingqing Zou, Yujie Zhao, Shenggao Wang, Yangwu Mao
Summary: In this study, the joining of Al2O3 ceramic to Cu using Ag-26.7Cu-4.5Ti braze and refractory metal (W or Ta) foil was conducted. It was found that the introduction of refractory metal foil can improve the shear strength of the joint. This is because the refractory metal foil can shift the residual stress distribution and decrease stress concentration in the joint, and the increase in the thickness of the Cu3Ti3O reaction zone also contributes to the improvement of joint strength.
CERAMICS INTERNATIONAL
(2022)
Article
Acoustics
Signe T. Heinemann, Janus W. Jensen, Sebastian von Osmanski, Ilmar F. Santos
Summary: There is no consensus on the best practice for modelling the compliant foil structure of Gas Foil Bearings (GFBs) in the literature. This paper focuses on the modelling of the top foil and compares four different top foil models (with and without gas injection) in terms of steady state analysis efficiency and accuracy. The results show that the model using Euler-Bernoulli beam elements is both computationally efficient and accurate for steady state analysis compared to the model using non-curved shell elements.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Chemistry, Analytical
Alan M. M. Gonzalez-Suarez, Alexander Long, XuHai Huang, Alexander Revzin
Summary: We present a control system for operating valve-enabled microfluidic devices and demonstrate its use in a complex workflow involving plasma separation and mixing. The control system includes pumps, pressure sensors, a microcontroller, solenoid valves, and off-the-shelf components, allowing precise fluid flow control.
Article
Biochemical Research Methods
Brian J. O'Grady, Michael D. Geuy, Hyosung Kim, Kylie M. Balotin, Everett R. Allchin, David C. Florian, Neelansh N. Bute, Taylor E. Scott, Gregory B. Lowen, Colin M. Fricker, Matthew L. Fitzgerald, Scott A. Guelcher, John P. Wikswo, Leon M. Bellan, Ethan S. Lippmann
Summary: Depositing a thin layer of parylene on 3D printed models allows them to be used as master molds for elastomeric device fabrication, making the prints biocompatible. Uncoated 3D prints can release toxic materials causing cell death, while parylene-coated prints can maintain cell viability and healthy morphology. This technique is simple and applicable for traditional microdevice fabrication and rapid prototyping of new designs.
Article
Biochemical Research Methods
Jingui Qian, Huaize Lan, Liang Huang, Shaohui Zheng, Xuefeng Hu, Minghui Chen, Joshua E. -Y. Lee, Wei Zhang
Summary: Trace biological sample detection is crucial in biomedical pathology analysis. An orthogonal tunable acoustic tweezer allows simultaneous droplet transport and centrifugation, enhancing sensitivity for biomarker detection.
Article
Engineering, Electrical & Electronic
N. Somjaijaroen, T. Kiss, K. Imamura, K. Higashikawa
Summary: By introducing deep learning-based image recognition, we have successfully detected local obstacles automatically in a 200-m-long conductor, which is significant for improving the reliability of the conductor.
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY
(2022)
Article
Engineering, Electrical & Electronic
Xavier Perpina, Miquel Vellvehi, Robert J. Werkhoven, Jiri Jakovenko, Jos M. G. Kunen, Peter Bancken, Pieter J. Bolt, Xavier Jorda
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2019)
Article
Energy & Fuels
M. Kovacic, J. Krc, B. Lipovsek, W. -C. Chen, M. Edoff, P. J. Bolt, J. van Deelen, M. Zhukova, J. Lontchi, D. Flandre, P. Salome, M. Topic
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2019)
Article
Physics, Applied
Sheng Yang, Samira Khelifi, Guy Brammertz, Leo Choubrac, Nicolas Barreau, Pieter Bolt, Bart Vermang, Johan Lauwaert
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2020)
Article
Chemistry, Multidisciplinary
Yvonne Kohl, Margit Biehl, Sarah Spring, Michelle Hesler, Vladimir Ogourtsov, Miomir Todorovic, Joshua Owen, Elisabeth Elje, Kristina Kopecka, Oscar Hernando Moriones, Neus G. Bastus, Peter Simon, Tibor Dubaj, Elise Runden-Pran, Victor Puntes, Nicola William, Hagen von Briesen, Sylvia Wagner, Nikil Kapur, Espen Mariussen, Andrew Nelson, Alena Gabelova, Maria Dusinska, Thomas Velten, Thorsten Knoll
Summary: Microfluidic technology provides a valuable tool for creating in vitro models that capture cellular and organ level responses for rapid and animal-free risk assessment of new chemicals and drugs. These cell-based devices allow high-throughput screening and flexible automation, reducing costs and reagent consumption due to miniaturization. The interconnected modules aim to simulate whole-body exposure and response, contributing to the replacement of animal testing in risk assessment studies in compliance with the 3Rs principles.
Article
Multidisciplinary Sciences
Kai Januschowski, Frank R. Ihmig, Timo Koch, Thomas Velten, Annekatrin Rickmann
Summary: The study aimed to improve the acceptance and compliance of amblyopia treatment by designing an electronic frame for context-sensitive liquid crystal glasses, which could measure the state of wear position and detect motion patterns for activity recognition. Results showed that the developed context-sensitive control algorithms were effective in detecting wear position and activity in a proof of concept study.
Review
Engineering, Electrical & Electronic
Agnes Beate Bussmann, Lorenz Maximilian Gruenerbel, Claudia Patricia Durasiewicz, Thomas Alexander Thalhofer, Axel Wille, Martin Richter
Summary: Research on microfluidic actuators for drug dosing applications is increasing, with micropumps showing promise in reducing size and energy consumption. Despite advantages, industrial microdosing units are limited and micropump technology is not widely applied. This work analyzes specific challenges and requirements in medical dosing, evaluates mechanical micropumps for drug administration, and presents technical solutions to ensure fluidic performance and meet medical microdosing requirements.
SENSORS AND ACTUATORS A-PHYSICAL
(2021)
Article
Chemistry, Multidisciplinary
Agnes Bussmann, Henry Leistner, Doris Zhou, Martin Wackerle, Yucel Congar, Martin Richter, Juergen Hubbuch
Summary: Subcutaneous injection is crucial for treating diseases, especially with automated dosing for better results. Research on MEMS-based drug delivery devices like a 5 x 5 mm² silicon micropump shows high dosing precision and repeatability, laying the foundation for extremely miniaturized patch pumps.
APPLIED SCIENCES-BASEL
(2021)
Article
Biotechnology & Applied Microbiology
Anke Schultz, Thorsten Knoll, Andreas Urban, Herbert Schuck, Hagen von Briesen, Anja Germann, Thomas Velten
Summary: Biosensors using novel materials like graphene produced through printing processes have potential applications in medical diagnostics, pharmaceuticals, and environmental technology. Printed graphene biosensors show promise in monitoring viruses and inhibiting their activity in the presence of antiviral drugs.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2021)
Article
Chemistry, Analytical
Agnes Bussmann, Thomas Thalhofer, Sophie Hoffmann, Leopold Daum, Nivedha Surendran, Oliver Hayden, Juergen Hubbuch, Martin Richter
Summary: The study demonstrates that using piezoelectric micro diaphragm pumps with suitable actuation signals for cell microfluidic transport can achieve optimal fluidic performance while minimizing damage to cells.
Article
Engineering, Mechanical
Martin Richter, Daniel Anheuer, Axel Wille, Yuecel Congar, Martin Wackerle
Summary: Fraunhofer EMFT's research focuses on piezoelectrically actuated silicon micro diaphragm pumps with passive flap valves. They propose cascading methods to achieve negative pressures using multistage systems of these micropumps. Measurement results show that a multistage of three micropumps can generate negative gas pressures down to -82.1 kPa relative to atmospheric pressure (19.2 kPa absolute). This research enables further miniaturization of high-performance applications requiring micropumps.
Article
Computer Science, Software Engineering
Johannes Schwarz, Kristjan Axelsson, Daniel Anheuer, Martin Richter, Johanna Adam, Martin Heinrich, Ruediger Schwarze
Summary: Classical continuum methods are inadequate for gas flows with higher Knudsen numbers. Various models have been developed in the past to extend the classical Navier-Stokes equations (CNSE) and incorporate the particle nature of the medium. One such approach considers the kinetic theory of gases, leading to the derivation of the extended Navier-Stokes equations (ENSE). Numerical methods, such as the Finite-Volume-Method, are commonly used to solve the CNSE, and this study utilizes the open-source tool OpenFOAM to develop an ENSE solver, which offers significant performance advantages by implicitly discretizing certain terms and defining additional diffusion face-flux fields. The results are validated against analytical formulas using a simple microchannel test case.
Article
Biotechnology & Applied Microbiology
Lorenz Gruenerbel, Ferdinand Heinrich, Jonathan Boehlhoff-Martin, Lynn Roeper, Hans-Guenther Machens, Arthur Gruenerbel, Moritz Schillinger, Andreas Kist, Franz Wenninger, Martin Richter, Leonard Steinbacher
Summary: As society ages, age-related diseases, such as pressure ulcers (PUs), are becoming more common. To prevent the development of PUs and reduce patient suffering and healthcare costs, a team has developed a sensor system capable of monitoring pressure load and tissue vital signs. In clinical studies, correlations were found between tissue perfusion and the risk of PU development, enabling the prediction of PU development in early stages.
BIOENGINEERING-BASEL
(2023)
Article
Nanoscience & Nanotechnology
Alisa Katsen-Globa, Andre Schulz, Norbert Puetz, Marcus Koch, Yvonne Kohl, Andreas W. Schneider-Ickert, Thomas Velten, Yuliya E. Silina
Summary: The study focuses on addressing global metal contamination through the development of advanced biomembrane technology using alginate scaffolds. Different conditions for the removal of various heavy metals and ruthenium were investigated, as well as their impact on cells. The findings provide insights into interactions within the biomaterial-inorganic system and potential applications for environmental protection.
ACS APPLIED BIO MATERIALS
(2021)
Proceedings Paper
Energy & Fuels
Juras Ulbikas, Vaidvile Ulbikaite, Julius Denafas, Robert Witteck, Marc Koentges, Marko Topic, F. Frontini, P. Bonomo, Philippe Mace, Pieter Jan Bolt, Alexander Ulyashin, Torstein Haarberg, Wolfram Palitzsch, Barbara Terheiden, Ingrid Weiss, Antonio Fuentes
2019 IEEE 46TH PHOTOVOLTAIC SPECIALISTS CONFERENCE (PVSC)
(2019)
Article
Chemistry, Physical
Bart Vermang, Guy Brammertz, Marc Meuris, Thomas Schnabel, Erik Ahlswede, Leo Choubrac, Sylvie Harel, Christophe Cardinaud, Ludovic Arzel, Nicolas Barreau, Joop van Deelen, Pieter-Jan Bolt, Patrice Bras, Yi Ren, Eric Jaremalm, Samira Khelifi, Sheng Yang, Johan Lauwaert, Maria Batuk, Joke Hadermann, Xeniya Kozina, Evelyn Handick, Claudia Hartmann, Dominic Gerlach, Asahiko Matsuda, Shigenori Ueda, Toyohiro Chikyow, Roberto Felix, Yufeng Zhang, Regan G. Wilks, Marcus Baer
SUSTAINABLE ENERGY & FUELS
(2019)
