A5000425819- Innovative Energy Harvesting Technologies
- Advanced Welding Techniques Analysis
- Piezoelectric Actuators and Control
- Electronic Packaging and Soldering Technologies
- Ultrasonics and Acoustic Wave Propagation
- Ultrasound and Cavitation Phenomena
- Welding Techniques and Residual Stresses
- Advanced Sensor and Energy Harvesting Materials
- Advanced MEMS and NEMS Technologies
- Energy Harvesting in Wireless Networks
- Adhesion, Friction, and Surface Interactions
- Laser and Thermal Forming Techniques
- Advanced machining processes and optimization
- 3D IC and TSV technologies
- Erosion and Abrasive Machining
- Surface Treatment and Residual Stress
- Acoustic Wave Resonator Technologies
- Wireless Power Transfer Systems
- Structural Health Monitoring Techniques
- Advanced Machining and Optimization Techniques
- Acoustic Wave Phenomena Research
- Aeroelasticity and Vibration Control
- Advanced Surface Polishing Techniques
- Mechanical Behavior of Composites
- Dynamics and Control of Mechanical Systems
Leibniz University Hannover
2016-2025
Nanjing University of Aeronautics and Astronautics
2020
RS Dynamics (Czechia)
2015-2017
Leibniz University of Applied Sciences
2013
Virginia Tech
2012
Heinz Nixdorf Stiftung
2006-2007
Paderborn University
2006-2007
Tuning porosity with electric fields Many metal-organic framework (MOF) compounds exhibit soft porosity—i.e., their lattices can undergo considerable deformation. Knebel et al. formed membrane layers of the MOF ZIF-8 and found that it was converted into a polar polymorph stiffer lattice in response to an applied field (see Perspective by Gascon). This change reduced gas transport but, for certain mixtures such as propane propene, also improved separation factor. Science , this issue p. 347 ; see 303
Various energy harvesting systems have been proposed in the last years. The use of ambient energy, such as vibration has evoked great interests. Most vibration-based converters generate maximum power only when generator is excited at its resonance frequency. To overcome this limitation, researchers focus on strategies for increasing working bandwidth an harvester. Due to amount different approaches broadband harvesting, we suggest a categorization. This review presents classification current...
Abstract This study describes multi-frequency Rayleigh wave excitation below 10 MHz, which is impossible with a conventional piezoelectric-single-crystal surface acoustic (SAW) device. To overcome this limitation, we utilized SAW device an elliptical reflector focusing structure (ELIPS). The prototype ELIPS excited on duralumin at 1.1 3.4 5.6 and 7.9 MHz in the single maximum vibration velocities were 0.38 m s −1 , 0.21 0.070 0.034 respectively, suggests possibility of high-power...
Despite the wide and long-term applications of ultrasonic (US) wire bonding other US metal joining technologies, mechanism microweld changes during process, including formation, deformation breakage, is rarely known as it very difficult to be investigated by experiments. In this work, under different surface topographies displacement patterns studied molecular dynamics simulation. It found that microwelds can formed or broken instantly. Due relative motion between local part substrate part,...
Ultrasonic turning has time variant parameters due to temperature effects and changing load conditions during the process. This results in a change of resonance frequency vibration amplitude. To realize constant amplitudes it is necessary control ultrasonic transducer by suitable feedback controller. One approach drive such system use as operating point connection with an amplitude The advantages resonant driven low damped systems are voltages high values effective power. paper presents...
This paper proposes a non-resonant linear ultrasonic motor utilizing longitudinal traveling waves. The waves in the rod type stator are generated by inducing vibrations at one end of waveguide and eliminating reflections opposite passive damper. Considering Poisson's effect, surface points move on elliptic trajectories slider is driven forward friction. In contrast to many other flexural wave motors, driving direction proposed identical propagation direction. feasibility concept demonstrated...
Abstract Laser beam welding is a commonly used technology for joining similar and dissimilar materials. In order to improve the mechanical properties of weld, introduction ultrasonic vibration into weld zone has been proposed [5]. The system consists an electronic control, power supply, piezoelectric converter sonotrode, which introduces zone. Its proper design great importance process performance. Furthermore, effects ultrasound in melt pool need be understood evaluate optimize parameters....
Acoustic levitation provides a means to achieve contactless manipulation of fragile materials and biological samples. Most acoustic levitators rely on complex electronic hardware software shape the field realize their dynamic operation. Here, authors introduce levitator that is based mechanically controlling opening (partial) closing subwavelength apertures. This simple approach relies use single ultrasonic transducer shown permit facile reliable variety targets ranging from solid particles,...
Laser beam welding is used in many areas of industry and research. There are strategies approaches to further improve the weld seam properties laser welding. Metallography often needed evaluate welded seams. Typically, images examined evaluated by experts. The evaluation process qualitatively provides welds. Particularly times when artificial intelligence being more processes, quantization that could previously only be determined gaining importance. In this contribution, we propose use deep...
Sonochemical processes applied to wastewater treatment have an influence on the behavior of ultrasonic systems. This is especially due load characteristic sonochemical process itself and temperature increase caused by internal damping within converter. Hence, a controlling device needed guarantee operation in resonance keep vibration amplitude constant. paper presents digital control system for weak strong damped devices its application inactivating Escherichia coli wastewater. In...