Publikationen der Arbeitsgruppe Piezo- und Ultraschalltechnik

Grajczak, J.; Reynders, D.; Nowroth, C.; Twiefel, J.; Wallaschek, J.; Nothdurft, S.; Hermsdorf, J.; Kaierle, S. (2024): Mechanisms of Increasing Weld Depth during Temporal Power Modulation in High-Power Laser Beam Welding,  Advanced Engineering Material, 2401386
DOI: https://doi.org/10.1002/adem.202401386

Long, Y.; Arndt, M.; Sun, C.; Dencker, F.; Wurz, M.; Twiefel, J. (2023): Detection of joining mechanisms at different locations of the wire/substrate interface during ultrasonic wire bonding via a PZT-based sensor array,  Journal of Materials Processing Technology, 312, 117826, 2023
DOI: doi.org/10.1016/j.jmatprotec.2022.117826

Merkel, P.; Budde, L.; Grajczak, J.; Nowroth, C.; Prasanthan, V.; Kriwall, M.; Lammers, M.; Nothdurft, S.; Hermsdorf, J.; Twiefel, J.; Overmeyer, L.; Kaierle, S.; Wallaschek, J.; Breidenstein, B.; Behrens, B.-A.; Stonis, M. (2023): Feasibility study for the manufacturing of hybrid pinion shafts with the cross-wedge rolling process,  International Journal of Material Forming, Vol. 16, No. 5, Springer Science and Business Media LLC, 2023-07
DOI: https://doi.org/10.1007/s12289-023-01761-4

Nowroth, C.; Grajczak, J.; Schmelt, A.; Nothdurft, S.; Twiefel, J.; Hermsdorf, J.; Kaierle, S.; Wallaschek, J. (2023): Feasibility study on multifrequency excitation of the melt pool during ultrasonic-assisted laser beam welding,  Ultrasonics, Vol. 131, Elsevier BV, p. 106954, 2023-05
DOI: https://doi.org/10.1016/j.ultras.2023.106954

Wang, F.; Sasamura, T.; Jiang, Y.; Miyake, S.; Twiefel, J.; Morita, T. (2023): Dynamic resonance frequency control for a resonant-type smooth impact drive mechanism actuator,  Sensors and Actuators A: Physical, 359, 114462, 2023
DOI: doi.org/10.1016/j.sna.2023.114462

Zhu, Y., Bengsch, S., Zheng, L., Long, Y., Roth, B.W., Wurz, M.C., Twiefel, J.; Wallaschek, J. (2021): Experimental Investigation of the Rapid Fabrication of Micron and Submicron Structures on Polymers Utilizing Ultrasonic Assisted Embossing,  Polymers, 13(15), p.2417

Grajczak, J.; Nowroth, C.; Saure, F.; Twiefel, J.; Wallaschek, J.; Coors, T.; Pape, F.; Poll, G.; Nothdurft, S.; Hermsdorf, J.; Wesling, V.; Kaierle, S. (2021): Influence of process-related heat accumulation of laser beam welded 1.7035 round bars on melt pool shape and welding defects,  J. Laser Appl. 33

Weinstein, M.; Nowroth, C.; Twiefel, J.; Wallaschek, J. (2021): Identification of the Effect of Ultrasonic Friction Reduction in Metal-Elastomer Contacts Using a Two-Control-Loop Tribometer,  Appl. Sci. 2021, 11, 6289

Bai, F.; Wang, L.; Yang, K.; He, Z.; Liu, C.; Twiefel, J. (2021): A novel inner surface enhancement method for holes utilizing ultrasonic cavitation,  Ultrasonics, 106453, 2021
DOI: doi.org/10.1016/j.ultras.2021.106453

Bai, F.; Wang, L.; Zang, K.; He, Z.; Qi, G.; Twiefel, J. (2021): Experimental Investigation of Peening Cylindrical Workpieces Utilizing a Transducer with Ring Sonotrode,  Applied Sciences, 11, 94, 2021
DOI: doi.org/10.3390/app11010094

Bai, F.; Wang, L.; Zang, K.; He, Z.; Qi, G.; Twiefel, J. (2021): Theoretical modeling and experimental investigation of a V-Shaped traveling wave piezoelectric transducer for ultrasonic cavitation Peening: Part B,  Applied Acoustics, 178, 107972, 2021
DOI: doi.org/10.1016/j.apacoust.2021.107972

Bai, F.; Wang, L.; Yang, K.; He, Z.; Xue, C.; Twiefel, J. (2021): Theoretical modeling and experimental investigation of a V-shaped traveling wave piezoelectric transducer for ultrasonic cavitation Peening: Part A,  Applied Acoustics, 178, 107971, 2021
DOI: doi.org/10.1016/j.apacoust.2021.107971

Hachisuka, S.; Yokozawa, H.; Wang, F.; Miyake, S.; Twiefel, J.; Morita T. (2021): Dynamic resonant frequency control system of ultrasonic transducer for non-sinusoidal waveform excitation,  Sensors and Actuators A: Physical, 113124
DOI: doi.org/10.1016/j.sna.2021.113124

Lu, X.; Twiefel, J.; Ma, Z.; Yu, T.; Wallaschek, J.; Fischer, P. (2021): Dynamic Acoustic Levitator Based On Subwavelength Aperture Control,  Adv. Sci. (Weinh), e2100888, 2021
DOI: doi.org/10.1002/advs.202100888

Ohrdes, H.; Nothdurft, S.; Nowroth, C.; Grajczak, J.; Twiefel, J.; Hermsdorf, J.; Kaierle, S. (2021): Influence of the ultrasonic vibration amplitude on the melt pool dynamics and the weld shape of laser beam welded EN AW-6082 utilizing a new excitation system for laser beam welding,  Prod. Eng. Res. Devel., 2021
DOI: doi.org/10.1007/s11740-020-01008-0

Twiefel, J.; Glukhovskoy, A.; de Wall, S.; Wurz, M.C.; Sehlmeyer, M.; Mitzemann, M.; Zimmermann, S. (2021): Towards a Highly Sensitive Piezoelectric Nano-Mass Detection—A Model-Based Concept Study,  Sensors (Basel), 21, 2533, 2021
DOI: doi.org/10.3390/s21072533

Schmelt, A.S.; Twiefel, J. (2020): The Spec-Radiation Method as a Fast Alternative to the Re-Radiation Method for the Detection of Flaws in Wooden Particleboards,  MDPI Appl. Sci. 2020, 10, 6663 | Datei |
DOI: https://doi.org/10.3390/app10196663

Schmelt, A.S.; Marhenke, T.; Hasener, J.; Twiefel, J. (2020): Investigation and Enhancement of the Detectability of Flaws with a Coarse Measuring Grid and Air Coupled Ultrasound for NDT of Panel Materials Using the Re-Radiation Method,  MDPI-applied science | Datei |
DOI: 10.3390/app10031155

Cao, T.; Li, X.; Wang, B.; Mi, Y.; Zhao, G.; Twiefel, J.; Wu, D. (2020): Viscoelastic analytical model and design of polymer-based bimodal piezoelectric motor,  Mechanical Systems and Signal Processing 145, S. 106960
DOI: https://doi.org/10.1016/j.ymssp.2020.106960

Grajczak, J.; Nowroth, C.; Nothdurft, S.; Hermsdorf, J.; Twiefel, J.; Wallaschek, J.; Kaierle, S. (2020): Influence of Ultrasound on Pore and Crack Formation in Laser Beam Welding of Nickel-Base Alloy Round Bars,  Metals 10 (10), S. 1299
DOI: 10.3390/met10101299

Lu, X.; Wang, Z.; Shen, H.; Zhao, K.; Pan, T.; Kong, D.; Twiefel, J. (2020): A Novel Dual-Rotor Ultrasonic Motor for Underwater Propulsion,  Applied Sciences 10 (1), S. 31
DOI: 10.3390/app10010031

Marhenke, T.; Neuenschwander, J.; Furrer. R.; Zolliker, P.; Twiefel, J.; Hasener, J.; Wallaschek, J.; Sanabria S.J. (2020): Air-Coupled Ultrasound Time Reversal (ACU-TR) For Subwavelength Nondestructive Imaging,  IEEE transactions on ultrasonics, ferroelectrics, and frequency control 67 (3), S. 651-663
DOI: 10.1109/TUFFC.2019.2951312.

Denkena, B.; Breidenstein, B.; Grove, T.; Prasanthan, V.; Overmeyer, L.; Nothdurft, S.; Kaierle, S.; Wallaschek, J.; Twiefel, J.; Ohrdes, H.; Maier, H. J.; Hassel, T.; Mildebrath, M.: (2019): Surface integrity of turned laser-welded hybrid shafts,  Production Engineering
DOI: 10.1007/s11740-018-0862-8

Nothdurft, S., Ohrdes, H., Twiefel, J., Wallascheck, J., Mildebrath, M., Maier, H. J., Hassel, T., Overmeyer, L., Kaierle, S. (2019): Influence of ultrasonic amplitude and position in the vibration distribution on the microstructure of a laser welded aluminum alloy,  Journal of Laser Applications 31

Andreas S. Schmelt, Viktor Hofmann, Eike C. Fischer, Marc C. Wurz, Jens Twiefel (2018): Design and characterization of the lateral actuator of a bimodal tactile display with two excitation directions,  Displays, Volume 54, September 2018, Pages 34-46 | Datei |
DOI: https://doi.org/10.1016/j.displa.2018.09.002

Nothdurft, S.; Springer, A.; Kaierle, S.; Mildebrath, M.; Maier, H. J.; Hassel, T.; Ohrdes, H.; Twiefel, J.; Wallaschek, J.; Overmeyer, L. (2018): Laser welding of dissimilar low-alloyed steel-steel butt joints and the effects of beam position and ultrasound excitation on the microstructure,  Journal of Laser Applications 30, 3, 032417

Kai-Alexander Saalbach, Jens Twiefel, Jörg Wallaschek (2018): Self-sensing cavitation detection in ultrasound-induced acoustic cavitation,  Ultrasonics
DOI: /10.1016/j.ultras.2018.06.016

Fushi Bai, Kai-Alexander Saalbach, Liang Wang, Xiaogeng Wang, Jens Twiefel (2018): Impact of time on ultrasonic cavitation peening via detection of surface plastic deformation,  Ultrasonics
DOI: /10.1016/j.ultras.2017.12.001

Kai-Alexander Saalbach, Hendrik Ohrdes, Jens Twiefel (2018): Closed Loop Cavitation Control - A Step Towards Sonomechatronics,  Ultrasonics Sonochemistry
DOI: /10.1016/j.ultsonch.2018.01.021

Aboulfotoh, N.; Twiefel, J. (2018): On developing an optimal design procedure for a bimorph piezoelectric cantilever energy harvester under a predefined volume,  Mechanical Systems and Signal Processing 106 (2018): 1-12

Bai, F., Saalbach, K.-A., Long Y., Twiefel, J., Wallaschek, J. (2018): Capability evaluation of ultrasonic cavitation peening at different standoff distances.,  Ultrasonics
DOI: /10.1016/j.ultras.2017.10.013

Long, Y.; Twiefel, J. and Wallaschek, J. (2017): A review on the mechanisms of ultrasonic wedge-wedge bonding,  Journal of Materials Processing Technology, 245, 2017, pp. 241-258

Hofmann, V.; Twiefel, J (2017): Self-Sensing with Loaded Piezoelectric Bending Actuators, Sensors and Actuators A,  Physical, Volume 263, August 2017, Pages 737-743

Wang, L.; Wielert, T.; Twiefel, J.; Jin, J.; Wallaschek, J. (2017): A Rod Type Linear Ultrasonic Motor Utilizing Longitudinal Traveling Waves: Proof of Concept,  Smart Materials and Structures, 26 (2017) 085013

Aboulfotoh, N.; Twiefel, J.; Krack, M. ; Wallaschek, J. (2017): Experimental Study on Performance Enhancement of a Piezoelectric Vibration Energy Harvester by applying Self-Resonating Behavior,  Energy Harvesting and Systems, Oct. 2017
DOI: 10.1515/ehs-2016-0027

Aboulfotoh, N.; Twiefel, J. (2017): A Study on Bandwidth and Performance Limitations of Array Vibration Harvester Configurations,  Energy Harvesting and Systems

Krack, M.; Aboulfotoh, N.; Twiefel, J.; Wallaschek, J.; Bergman, L.A.; Vakakis, A.F. (2017): Toward understanding the self-adaptive dynamics of a harmonically forced beam with a sliding mass,  Archive of Applied Mechanics

Bai, F., Saalbach, K.-A., Twiefel, J., & Wallaschek, J. (2017): Effect of different standoff distance and driving current on transducer during ultrasonic cavitation peening.,  Sensors and Actuators A: Physical.
DOI: /10.1016/j.sna.2017.05.002

Ohrdes, H.; Ille, I.; Twiefel, J.; Wallaschek, J.; Nogueira, R.; Rosenwinkel, K. H. (2017): A control system for ultrasound devices utilized for inactivating E. coli in wastewater,  Ultrasonics Sonochemistry
DOI: 10.1016/j.ultsonch.2017.04.017

Marhenke, T.; Twiefel, J.; Hasener, J. (2016): Transiente Ultraschallfeldvisualisierung von Transmissionsvorgängen an Platten auf Basis der Refraktovibrometrie,  TM – Technisches Messen 83, 10, pp. 580-592, October
DOI: 10.1515/teme-2016-0003

Brouet, F.; Twiefel, J.; Wallaschek, J. (2016): Modal interaction in ultrasonic welding block sonotrodes induced by the mistuning of the material properties,  Journal of Sound and Vibration 318, pp. 1-13, October
DOI: 10.1016/j.jsv.2016.06.021

Aboulfotoh, N.; Krack, M.; Twiefel, J.; Wallaschek, J. (2016): A Self-Resonant System-Experimental Investigations of Boundary and Operating Conditions,  PAMM 16, 1, pp. 253-254, October
DOI: 10.1002/pamm.201610115

Van Drunen, W. J.; Hofmann, V.; Twiefel, J.; Glukhovskoy, A.; Beringer, S.; Wurz, M. C.; Rau, T. S.; Wallaschek, J.; Rissing, L.; Lenarz, L.; Majdani, O. (2016): Track P. Medical Implants/Implant Development,  Biomedical Engineering 61, 1, pp. 179-199
DOI: 10.1515/bmt-2016-5014
ISBN: ISSN (online) 1862-278X, ISSN (print) 0013-5585

Bruns, P.; Mojrzisch, S.; Twiefel, J.; Wallaschek, J.; Zimmermann, U.; Klie, W. (2016): Prüfstand mit piezoelektrischen Schwingungserzeugern zur Ermittlung der dynamischen Steifigkeit von Elastomerbauteilen,  Forschung im Ingenieurwesen 80, 1-2, pp. 29-40 June
DOI: 10.1007/s10010-016-0204-y

Saalbach, K.; Twiefel, J.; Wallaschek, J. (2016): 1945. Self-sensing cavitation detection capability of horn geometries for high temperature application,  Journal of Vibroengineering 18, 2, pp. 989-998, March

Hofmann, V.; Twiefel, J.; Glukhovskoy, A.; Beringer, S.; Wurz, M. C.; Wallaschek, J.; Rissing, L. (2016): Intracochlear Stimulation of the Basilar Membrane,  Biomed Tech 61, p.179
DOI: 10.1515/bmt-2016-5014

Brouet, F.; Twiefel, J.; Wallaschek, J. (2015): Frequency veering and mode degeneration of a rectangular disc,  PAMM 15 (1), 175-176
DOI: 10.1002/pamm.201510078

Saalbach, K.; Wurz, M. C.; Twiefel, J.; Rissing, L.; Wallaschek J. (2015): Custom Lithium Niobate Transducers for Detecting Material Distribution of Hybrid Workpieces,  Energy Harvesting and Systems. Band 2, Heft 3-4, Seiten 137–142
DOI: 10.1515/ehs-2014-0045
ISBN: ISSN (Online) 2329-8766, ISSN (Print) 2329-8774

Hofmann, V.; Kleyman, G.; Twiefel, J. (2015): Modeling and Experimental Investigation of a Periodically Excited Hybrid Energy-Harvesting Generator,  Energy Harvesting and Systems
DOI: 10.1515/ehs-2014-0043

Hofmann, V.; Twiefel, J. (2015): Optimization of a Piezoelectric Bending Actuator for a Tactile Virtual Reality Display,  Energy Harvesting and Systems

Stehle, T.; Eisseler, R.; Drewle, K.; Weiland, S.; Bruns, P.; Twiefel, J. (2015): Investigation of Process Forces of Ultrasonically Assisted Scratch Tests,  Proceedings of the 3rd International Conference on Stone and Concrete Machining (ICSCM), November 2-3, Bochum, S. 137-145
DOI: 10.13154/icscm.3.2015.137-145

Bruns, P.; Twiefel, J. (2015): Influences of Non-axial Process Loads on the Transducer and the Associated Mounting in Ultrasonic Machining,  Energy Harvesting and Systems
DOI: 10.1515/ehs-2014-0022
ISBN: ISSN (Online) 2329-8766, ISSN (Print) 2329-8774

Heisel, U., Eisseler, R., Eber, R., Wallaschek, J., Twiefel, J., Huang, M. (2012): Ultrasonic-assisted machining of stone,  Production Engineering, 6 (2), pp. 587-594
DOI: 10.1007/s11740-011-0330-1

Wurpts, W.; Twiefel, J. (2012): Analysis of Ultrasonic Vibro-Impact Systems with Equivalent Circuits and the Harmonic Balance Method,  Sensors and Actuators A: Physical, Elsevier
DOI: 10.1016/j.sna.2012.10.007

Heisel, U.; Eber, R.; Wallaschek, J.; Twiefel, J. (2011): Kinematic model for ultrasonic-assisted manufacturing of bore holes with undefined cutting edges,  Journal of Advanced Materials Research 223 (2011), pp. 794 – 803
DOI: 10.4028/www.scientific.net/AMR.223.794

Neubauer, M.; Renner, A.; Twiefel, J. (2010): Stability Analysis of a Disc Brake with Piezoelectric Self-Sensing Technique,  SAE International Journal of Passenger Cars – Mechanical Systems, Vol. 2, No. 2, pp. 24-31
DOI: 10.4271/2009-01-3034
ISBN: 1946-4002

Shi, J.; Twiefel, J.; Wallaschek, J. (2020): Optical Visualization of Dynamic Stress Waves in Transparent Solids,  Spartially, Temporally and Spectrally Adapted Light for Applications: Progress Report of the Lower Saxony PhD Scholarship Program Tailored Light, 1. Erstausgabe; Lachmayer, R., Roth, B., Wolf, A., Eds.; TEWISS: Garbsen, 2020; pp 45–48
ISBN: 978-3-95900-424-4

Zijian Chen; Jens Twiefel; Joerg Wallaschek (2024): High-Accuracy Alignment of integrated Optical Components utilizing Ferroelectric Shape-Memory Actuators,  Proceedings of Actuator 2024: International Conference and Exhibition on New Actuator Systems and Applications, June 13-14, Wiesbaden, Germany, 2024
ISBN: 978-3-8007-6391-7

Grajczak, J.; Nowroth C.; Twiefel, J.; Wallaschek, J.; Nothdurft, S.; Hermsdorf, J.; Kaierle, S. (2024): Ultraschallunterstütztes Laserstrahlschweißen zur Erzeugung umformbarer Mischverbindungen,  24. Umformtechnisches Kolloquium Hannover (UKH), 13. März, Deutschland, 2024

Grajczak, J.; Nowroth, C.; Twiefel, J.; Wallaschek, J.; Nothdurft, S.; Hermsdorf, J.; Kaierle, S. (2024): Ultraschallunterstütztes Laserstrahlschweißen von Rundstangen,  CZM-Absolvententag, 12. Juli, Clausthal-Zellerfeld, Deutschalnd, 2024

Nowroth, C.; Morita, T.; Grajczak, J.; Nothdurft, S.; Hermsdorf, J.; Twiefel, J.; Kaierle, S.; Wallaschek, J. (2024): Vibration Shape Tuning Using Passive Piezo Elements for the Ultrasonic-Assisted Laser Beam Welding,  International Workshop on Piezoelectric Materials and Applications in Actuators (IWPMA), Hannover, Germany, 2024

Arndt, M.; Long, Y.; Hu, C.; Dencker, F.; Twiefel, J.; Wurz, M. (2023): Manufactruing and Characterization of Piezoelectric Force Sensor Arrays for Investigation of Ultrasonic Wire Bonding,  MikroSystemTechnik Kongress 2023, Oktober 23-25, Dresden, Deutschland, 2023

Hadeler, S.; Long, Y.; Ottermann, R.; Dencker, F.; Twiefel, J.; Wurz, M.C (2023): Influence of Microscale Tin Particles on Mechanical Properties of Silver Sintering Joints with Reduced Processing Parameters,  2023 IEEE 73rd Electronic Components and Technology Conference (ECTC). 2023 IEEE 73rd Electronic Components and Technology Conference (ECTC), Orlando, FL, USA, 5/30/2023 - 6/2/2023; IEEE, 2023 - 2023; pp 676–681
ISBN: 979-8-3503-3498-2

Hadeler, S.; Long, Y.; Twiefel, J.; Wurz, M.C. (2023): Measurement of the Ultrasound Induced Temperature Change in an Ultrasonic Assisted Silver Sintering Process,  2023 IEEE SENSORS. 2023 IEEE SENSORS, Vienna, Austria, 29 Oct.–01 Nov. 2023; IEEE, 2023; pp 1–4
ISBN: 979-8-3503-0387-2

Nowroth, C.; Grajczak, J.; Nothdurft, S.; Hermsdorf, J.; Twiefel, J.; Kaierle, S.; Wallaschek, J. (2021): Investigations regarding the correlation between the driving signals of an ultrasonic transducer and the process data during ultrasonic-assisted laser beam welding,  18th International Workshop on Piezoelectric Materials and Applications in Actuators, IWPMA, 2021

Arndt, M., Long, Y., Dencker, F., Reimann, J., Twiefel J., Wurz, M. (2020): Novel Piezoelectric Force Sensor Array for Investigation of Ultrasonic Wire Bonding,  Electronic Components and Technology Conference (ECTC), Jun. 3-30, Orlando, USA, pp.276-283
DOI: 10.1109/ECTC32862.2020.00053

Schmelt, A.S.; Li, Z.; Marhenke, T.; Hasener, J.; Twiefel, J. (2020): Aussagefähigkeit von Fehlstellenimitaten in der ZfP,  Tagungsband DAGA 2020 - 46. Jahrestagung für Akustik | Datei |
ISBN: 978-3-939296-17-1

Wang, L.; Wang, X.; Twiefel, J.; Jin, J.; Xu, Q. (2020): Design of a Novel Surface-Bonded Type of Linear Ultrasonic Motor With Single-Phase Excitation,  2020 IEEE 16th International Conference on Automation Science and Engineering (CASE), Hong Kong, Hong Kong, 20–21 Aug. 2020; IEEE, 2020 - 2020; pp 1078–1083
ISBN: 978-1-7281-6904-0

A. S. Schmelt; E. C. Fischer; V. Hofmann; J. Twiefel; M. C. Wurz (2019): Vibro-tactile displays for stimulating surface impressions,  PROCEEDINGS of the 23rd International Congress on Acoustics 9 to 13 September 2019 in Aachen, Germany, pp. 1000-1007 | Datei |
ISBN: ISSN 2226-7808 and 2415-1599 ISBN 978-3-939296-15-7

A. S. Schmelt; T. Marhenke; J. Twiefel (2019): Identifying objects in a 2D-space utilizing a novel combination of a re-radiation based method and of a difference-image-method,  PROCEEDINGS of the 23rd International Congress on Acoustics 9 to 13 September 2019 in Aachen, Germany, pp. 8156-8163 | Datei |
ISBN: ISSN 2226-7808 and 2415-1599 ISBN 978-3-939296-15-7

A. S. Schmelt, E. C. Fischer, M. C. Wurz and J. Twiefel (2018): Solid State Joint Actuator for a Vibro Tactile Line Display,ACTUATOR 2018; 16th International Conference on New Actuators, Bremen, Germany, 2018, pp. 1-4,  VDE Verlag | Datei |
ISBN: 978-3-8007-4675-0

Behrens, B.A., Chugreev, A.; Matthias, T.; Nothdurft, S.; Hermsdorf, J.; Kaierle, S.; Ohrdes, H.; Twiefel, J.; Wallaschek, J.; Mildebrath, M.; Hassel, T. (2018): Investigation of the composite strength of hybrid steel-steel semi-finished products manufactured by laser beam welding and friction welding,  5TH INTERNATIONAL CONFERENCE of recent trends in structural materials (COMAT), 14.-16.11.2018, Pilsen
DOI: 10.1088/1757-899X/461/1/012049

Long, Y.; Dencker, F.; Isaak, A.; Schneider, F.; Hermsdor, J.; Wurz, M.; Twiefel, J. (2017): Visualization of Oxide Removal during Ultrasonic Wire Bonding Process,  19th IEEE Electronics Packaging Technology Conference (EPTC), Dec 6-9, 2017 Singapore, S. 1-4

Long, Y.; Dencker, F.; Isaak, A.; Li, C.; Schneider, F.; Hermsdor, J.; Wurz, M.; Twiefel, J.; Wallaschek, J. (2017): Analysis of the Wire/Substrate Interface during Ultrasonic Bonding Process,  IEEE CPMT Symposium Japan (ICSJ), Nov 20-22, 2017 Kyoto, Japan, S. 203-206

Fischer, E.; Glukhovskoy, A.; Schmelt, A., S.; Twiefel, J.; Wurz, M.,C. (2017): Mikroaktorik für ein Taktiles Display,  Proceedings of the MikroSystemTechnik Kongress 2017, October 23–25, 2017 München, S. 515-518

Marhenke, T.; Twiefel, J.; Hasener , J.; Wallaschek, J. (2017): Ermittlung mechanischer Kennwerte von Holzwerkstoffen mittels Modal-Updating,  Proceedings der 35. CADFEM Simulation Conference, November 15-17, Koblenz, Deutschland

Hofmann, V.; Twiefel, J. (2017): Cultivator Optimization for Ultrasonic Friction Reduction using the Transfer Matrix Modeling Method,  The International Workshop on Piezoelectric Materials and Applications in Actuators, Falls Church, VA, USA

Schneider, F.; Long, Y.; Ohrdes, H.; Twiefel, J.; Brökelmann, M.; Hunstig, M.; Venkatesh, A.; Hermsdorf, J.; Kaierle, S.; Overmeyer, L (2017): Effect of laser assistance in ultrasonic copper wire bonding ,  Lasers in Manufacturing Conference 2017

Marhenke, T.; Twiefel, J.; Hasener , J.; Wallaschek, J. (2017): Determination of Mechanical Properties of Wood Based Materials using Modal Updating,  Proceedings of the IEEE International Ultrasonics Symposium (IEEE IUS), September 6-9, Washingstion D.C., USA, 2017

Bruns, P.; Twiefel, J.; Wallaschek, J. (2017): Modeling of ultrasonic processes utilizing a generic software framework,  IOP Conference Series: Materials Science and Engineering, Vol. 211. No. 1, IOP Publishing, 2017

Nothdurft, S.; Springer, A.; Kaierle, S.; Mildebrath, M.; Maier, H. J.; Hassel, T.; Ohrdes, H.; Twiefel, J.; Wallaschek, J.; Overmeyer, L. (2017): Influence of beam position and ultrasonic amplitude on the microstructure of laser welded dissimilar steel-steel joints,  International Congress on Applications of Lasers & Electro-Optics (ICALEO®), 22.-26.10.2017, Atlanta

Long, Y.; Dencker, F.; Schneider, F.; Emde, B.; Li, C.; Hermsdorf, J.; Wurz, M.; Twiefel, J. (2016): Investigations on the Oxide Removal Mechanism during Ultrasonic Wedge-Wedge Bonding Process,  IEEE 18th Electronics Packaging Technology Conference, November 30 - December 3, Singapore, Southeast Asia, pp. 405-410

Long, Y.; Dencker, F.; Wurz, M.; Feldhoff, A.; Twiefel, J. (2016): A deeper understanding on the motion behaviors of wire during ultrasonic wedge-wedge bonding process,  International Symposium on Microelectronics, October 10-13, Pasadena, USA, pp. 427-432

Ohrdes, H.; Fischer, H.; Twiefel, J.; Wallaschek J. (2016): Experimental investigation of ultrasonic fluid mixing as assistance for a laser welding process,  Proceedings of ISMA2016: International Conference on Noise and Vibration Engineering, September 19-21, Leuven, Belgium, pp. 1595-1603

Wielert, T.; Vagapov, A.; Twiefel, J.; Mešan, I.; Bott, K. (2016): Performance of a Novel Small Component Conveyor Utilizing Flexural Travelling Waves,  Conference Proceedings of ACTUATOR 2016, 15th International Conference on New Actuators, June 13-15, Bremen, Germany

Bruns, P.; Twiefel, J.; Wallaschek, J. (2016): Experimental and Theoretical Investigation of a Vibro-Impact Process Utilizing an in situ Capacitive Distance Measurement,  Proceedings of ISMA2016 International Conference on Noise and Vibration Engineering, September 19-21, Leuven, Belgium

Marhenke, T.; Twiefel, J.; Wallaschek, J. (2016): Zerstörungsfreie Delaminationserkennung mittels luftgekoppeltem Ultraschall,  Tagungsband der 14. Vibrometerkonferenz der Polytec GmbH: Einsatz Optischer Schwingungsmesstechnik in Industrie und Forschung, November 22-23, Waldbronn, Germany

Marhenke, T.; Twiefel, J.; Wallaschek, J. (2016): Delaminationserkennung in Holzwerkstoffen auf Basis der Ultraschalltransmissionsmessung,  Tagungsband des 3. Workshop des Fachausschusses Ultraschall der DEGA e.V.: Messtechnische Anwendungen von Ultraschall, June 20-22, Drübeck, Germany

Schmidt, M.;Reinke, P.; Beckmann, T.; Saalbach, K. A.; Wallaschek, J.; Twiefel, J.; Bai, F. (2016): Numerical and experimental investigation of the levitation and flow created by ultrasonic fields in narrow gaps,  5th Micro and Nano Flows Conference

Aboulfotoh, N.; Twiefel J. (2016): A Study on the Influence of Design Parameters on the Power Output Characteristic of Piezoelectric Vibration Energy Harvester,  Proceedings of the 27th International Conference on Noise and Vibration Engineering, ISMA, Leuven

Ertz, G.; Twiefel, J.; Secanell, M.; Mertiny, P. (2015): Design and Manufacturing of a Scalable Composite Flywheel Demonstrator for Mobile Energy Storage System,  CANCOM, August 17-20, Edmonton, Canada

Ertz, G.; Krack, M.; Twiefel, J.; Secanell, M.; Mertiny, P. (2015): Skalierbarer Demonstrator für Mobile Schwungradspeichersysteme,  VDI Mechatroniktagung, März 12-13, Dortmund, Deutschland

Wielert, T.; Twiefel, J.; Mešan, I.; Bott, K. (2015): Kleinteileförderung mit einem ultraschallbasierten Wanderwellentransportsystem,  Tagungsband Mechatronik 2015
ISBN: 978-3-00-048814-6

Long, Y.; Twiefel, J.; Roth, J.; Wallaschek, J. (2015): Real-time observation of interface relative motion during ultrasonic wedge-wedge bonding process,  In International Symposium on Microelectronics, IMAPS (International Microelectronics, Assembly and Packaging Society), pp. 419-424

Weinstein, M.; Ille, I.; Mojrzisch, S.; Twiefel, J.; Wallaschek, J. (2015): Resonance Frequency Tuning of Piezoelectric Ultrasonic Transducers Using Resonant Switching Converters,  Third International Academic Conference of Postgraduates, NUAA, Nanjing, China

Bruns, P.; Twiefel, J.; Wallschek, J. (2015): Investigations on the Mounting Position of Ultrasonic Transducers,  The 12th International Workshop on Piezoelectric Materials and Applications in Actuators, Vilnius

Bruns, P.; Mojrzisch, S.; Twiefel, J.; Wallaschek, J.; Klie, W.; Zimmermann, U. (2015): Piezoelektrische Schwingungserzeuger zur Ermittlung der dynamischen Steifigkeiten von Elastomerbauteilen,  VDI Mechatroniktagung, Dortmund

Roth, J.; Twiefel, J.; Wallaschek, J. (2013): Energy Harvesting Patents 2012,  Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, Hannover, Germany

Wallaschek, J.; Saalbach, K.; Twiefel, J. (2013): Soundfield Design for Ultrasonically Assisted Composite Casting,  Proceedings of 11th International Conference on Vibration Problems

Saalbach, K.; Freytag, P.; Kerber, K.; Twiefel, J. (2013): Bond Quality Investigation of Ultrasonic Assisted Composite Casting,  Proceedings of 10th International Workshop on Piezoelectric Materials and Applications and 8th Energy Harvesting Workshop, July 14-17, Hannover, Germany
ISBN: 978-3-944586-10-6

Saalbach, K.; Freytag, P.; Kerber, K.; Twiefel, J. (2013): Ultrasonic Assisted Simultaneous Composite Casting – a Feasibility Study,  Ultrasonics Symposium (IUS), 2012 IEEE International-Proceedings

Wurpts, W.; Bruns, P.; Twiefel, J. (2013): A Transfer Matrix Method for the Design of Resonant Piezoelectric Devices,  10th International Workshop on Piezoelectric Materials and Applications, Hannover, Germany

Bruns, P.; Mojrzisch, S.; Twiefel, J. (2013): Stress Distribution and Durability of Pre-Stressed Piezoelectric Multilayer Actuators,  10th International Workshop on Piezoelectric Materials and Applications, Hannover, Germany

Mojrzisch, S.; Ille, I.; Twiefel J. (2012): Driving methods and control design for high power ultrasonic transducers,  9th International Workshop on Piezoelectric Materials and Applications in Actuators, Hirosaki, Japan

Bruns, P.; Mojrzisch, S.; Twiefel, J.; Wallaschek, J. (2012): Autoresonant Control of an Electromagnetic Linear Actuator with Piecewise-Linear Restoring Force,  13th Mechatronics Forum International Conference, Linz, Austria

Neubauer, M.; Twiefel, J.; Westermann, H.; Wallaschek, J. (2012): Modeling Aspects of Nonlinear Energy Harvesting for Increased Bandwidth,  Small-Scale Energy Harvesting, Edited by M. Lallert, InTech, Chapter 13
DOI: 10.5772/52232
ISBN: 978-953-51-0826-9

Richter, B.; Twiefel, J.; Wallaschek, J. (2009): Piezoelectric Equivalent Circuit Models,  In: Priya, S.; Inman, D. J. (Hrsg.): Energy Harvesting Technologies, pp. 107-128
DOI: 10.1007/978-0-387-76464-1_4
ISBN: 978-0-387-76463-4

Ohrdes, H.; Twiefel, J. ; Wallaschek, J.; Nogueira, R.; Rosenwinkel, K. H. (2016): A feasibility study on the use of ultrasound for inactivating E. Coli in raw and treated wastewater,  2nd International Conference on Ultrasonic-based Applications: from analysis to synthesis - Ultrasonics 2016

B. Richter; J. Twiefel; T. Hemsel; J. Wallaschek (2006): Model Based Design of Piezoelectric Generators Utilising Geometrical and Material Properties

Marin, A.; Heitzmann, P.; Twiefel, J.; Priya, S. (2012): Improved pen harvester for powering a pulse rate sensor,  Proc. of SPIE Vol. 8341, 83411D-1

Kattenstroth, R.; Harms, H.-H.; Wurpts, W.; Twiefel, J.; Wallaschek, J. (2011): Reibkraftreduktion mittels Ultraschallanregung in der Bodenbearbeitung,  Landtechnik Band 66 Heft 1, pp. 10-13
DOI: 10.15150/lt.2011.341

Zhao, S.; Twiefel, J.; Wallaschek, J. (2009): Design and experimental investigations of high power piezoelectric transducers for a novel squeeze film journal bearing,  Proc. SPIE, Vol. 7288, Active and Passive Smart Structures and Integrated Systems, San Diego, CA, USA

Twiefel, J.; Klubal, M.; Paiz, C.; Mojrzisch, S.; Kruger, H. (2008): Digital signal processing for an adaptive phase-locked loop controller,  Proc. SPIE 6926, 69260A
DOI: 10.1117/12.776091

Twiefel, J.; Potthast, C.; Mracek, M.; Hemsel, T.; Sattel, T.; Wallaschek, J. (2008): Fundamental Experiments as Benchmark Problems for modeling Ultrasonic Micro-Impact Processes,  Journal of Electroceramics, 2008, 20 (3-4), S. 209-214
DOI: 10.1007/s10832-007-9169-4

Twiefel, J.; Richter, B.; Sattel, T.; Wallaschek, J. (2008): Power Output Estimation and Experimental Validation for Piezoelectric Energy Harvesting Systems,  Journal of Electroceramics, 2008, 20 (3-4), S. 203-208
DOI: 10.1007/s10832-007-9168-5

Potthast, C.; Twiefel, J.; Wallaschek, J. (2007): Modeling Approaches for an Ultrasonic Percussion Drill,  Journal of Sound and Vibration, S. 405-417

Potthast, C.; Twiefel, J.; Wallaschek, J. (2007): Model based Analysis of an Ultrasonic Percussion Drill,  In: ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering

Richter, B.; Twiefel, J.; Hemsel, T.; Wallaschek, J. (2007): Model Based Design of Piezoelectric Generators Utilising Geometrical and Material Properties,  2006 International Mechanical Engineering Congress & Exposition (IMECE 2006), 5-10 November, Chicago, Illinois, USA

Richter, B.; Twiefel, J.; Sattel, T.; Wallaschek, J. (2007): Design Method for Piezoelectric bending Generators in Energy Harvesting Systems,  In: Active and Passive Smart Structures and Integrated Systems 2007, San Diego, USA, SPIE, 2007, Bd. 6525, Nr. 652504

Twiefel, J.; Potthast, C.; Mracek, M.; Hemsel, T.; Sattel, T.; Wallaschek, J. (2007): Fundamental Experiments as Benchmark Problems for modelling Ultrasonic Micro-Impact Processes,  Journal of Electroceramics
DOI: 10.1007/s10832-007-9169-4
ISBN: ISSN 1385-3449

Twiefel, J.; Richter, B.; Sattel, T.; Wallaschek, J. (2007): Power output Estimation and Experimental Validation for Piezoelectric Energy Harvesting Systems,  In: Journal of Electroceramics
DOI: 10.1007/s10832-007-9168-5
ISBN: ISSN 1385-3449