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Tuluk, A. (author), Mahon, T.R. (author), van der Zwaag, S. (author), Groen, W.A. (author)BiFeO<sub>3</sub> is an interesting multiferroic material with potential use in sensors and transducers. However, the high coercive field and low dielectric strength of this material make the poling process extremely difficult. Poling becomes a lot easier if the ceramic particles are incorporated in a non-conductive polymer with comparable...journal article 2021
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Mahon, T.R. (author), Giannopoulos, D. (author), van der Zwaag, S. (author), Groen, W.A. (author)In this work, we present the impact of using Na<sub>2</sub>CO<sub>3</sub> as a sintering aid and grain growth agent on the crystal structure, microstructure, and piezoelectric properties of (Bi<sub>0.5</sub>Na<sub>0.5</sub>)TiO<sub>3</sub> ceramics. The addition of Na<sub>2</sub>CO<sub>3</sub> leads to a substantial increase in the grain size...journal article 2021
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Tselikos, Georgios (author), Rasul, Shahid (author), Groen, W.A. (author), Li, Chunchun (author), Khaliq, Jibran (author)Three-dimensional printing-based additive manufacturing has emerged as a new frontier in materials science, with applications in the production of functionalized polymeric-based hybrid composites for various applications. In this work, a novel conceptual design was conceived in which an AC electric field was integrated into a commercial 3D...journal article 2021
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Giannopoulos, D. (author), Chen, Yu Chen (author), van der Zwaag, S. (author), Groen, W.A. (author)Piezoelectric transducers which rely on oscillating cantilever-type beams to harvest mechanical energy locally available in environments have been of great interest as a substitute for batteries. Most of the research efforts focus mostly on designs which aim at resonance matching to achieve maximum energy output without taking the mechanical...journal article 2021
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Mkhoyan, T. (author), Stuber, V.L. (author), Nazeer, N. (author), De Breuker, R. (author), Groves, R.M. (author), Groen, W.A. (author), van der Zwaag, S. (author), Sodja, J. (author), Wang, X. (author)PowerPoint presentationother 2020
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van Kempen, S. E. (author), Khanbareh, H. (author), Groen, W.A. (author), Hol, J.M.A.M. (author), van der Zwaag, S. (author)A novel method based on the Virtual Particle Mori–Tanaka (VPMT) is developed to predict the effective electro-elastic properties, d<sub>33</sub> and g33, of structured piezoelectric particulate composites with improved accuracy by means of a single parameter related to the spatial distribution of imperfectly aligned rod-like PZT particles....journal article 2020
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Steijlen, A.S.M. (author), Bastemeijer, J. (author), Groen, W.A. (author), Jansen, K.M.B. (author), French, P.J. (author), Bossche, A. (author)A wide variety of electrochemical sweat sensors are recently being developed for real-time monitoring of biomarkers. However, from a physiological perspective, little is known about how sweat biomarkers change over time. This paper presents a method to collect and analyze sweat to identify inter and intraindividual variations of electrolytes...conference paper 2020
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Zhang, Yan (author), Hopkins, Margaret A. (author), Liptrot, David J. (author), Khanbareh, Hamideh (author), Groen, W.A. (author), Zhou, Xuefan (author), Zhang, Dou (author), Bao, Yinxiang (author), Zhou, Kechao (author), Bowen, Chris R. (author), Carbery, David R. (author)We demonstrate that trimethylamine borane can exhibit desirable piezoelectric and pyroelectric properties. The material was shown to be able operate as a flexible film for both thermal sensing, thermal energy conversion and mechanical sensing with high open circuit voltages (>10 V). A piezoelectric coefficient of d<sub>33</sub>≈10–16 pC N...journal article 2020
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Deutz, D.B. (author), van der Zwaag, S. (author), Groen, W.A. (author)As demand rises for flexible electronics, traditionally prepared sintered ceramic sensors must be transformed into fully new sensor materials that can bend and flex in use and integration. Negative temperature coefficient of resistance (NTC) ceramic thermistors are preferred temperature sensors for their high accuracy and excellent stability,...journal article 2020
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Leandro Cruz, M. (author), van den Bogaard, M.E.D. (author), Saunders-Smits, Gillian (author), Groen, W.A. (author)Contribution: This study reports on a reliable and valid instrument that measures engineering students' perceptions of their competency levels. A better understanding of students' needs in engineering curricula will support the development of engineering students' transversal competencies. Background: Prior research has investigated how...journal article 2020
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Heijboer, S.E.H. (author), Tempelman, E. (author), Schumann, Josef (author), Groen, W.A. (author)Current transformational developments in automotive user interface (UI) technology are causing a shift in emphasis from safety and efficiency to emotion and flexibility. The many factors to consider in parallel make this a difficult process, in which technological affordances all too easily push the user to the background. To address this...conference paper 2019
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- Leandro Cruz, M. (author), Saunders-Smits, Gillian (author), Groen, W.A. (author) poster 2019
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- Leandro Cruz, M. (author), Saunders-Smits, Gillian (author), Groen, W.A. (author) poster 2019
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Groen, W.A. (author)Onderzoekers van Holst Centre en Fraunhofer FEB produceerden eind 2018 een oled-rol van 15 meter; ‘s werelds langste verlichtingsdevice uit 1 stuk. Pim Groen, professor aan de TU Delft en projectleider Large Area Printing bij Holst Centre<br/>markeert deze prestatie als een absolute gamechanger. ‘We hebben nu aangetoond dat opschaling naar...journal article 2019
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Leandro Cruz, M. (author), Saunders-Smits, Gillian (author), Groen, W.A. (author)The purpose of this systematic review is to evaluate the state-of-the-art of competency measurement methods with an aim to inform the creation of reliable and valid measures of student mastery of competencies in communication, lifelong learning, innovation/creativity and teamwork in engineering education. We identified 99 studies published in...review 2019
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Zhao, Dong (author), Lenz, Thomas (author), Gelinck, Gerwin H. (author), Groen, W.A. (author), Damjanovic, Dragan (author), de Leeuw, D.M. (author), Katsouras, Ilias (author)Depolarization in ferroelectric materials has been studied since the 1970s, albeit quasi-statically. The dynamics are described by the empirical Merz law, which gives the polarization switching time as a function of electric field, normalized to the so-called activation field. The Merz law has been used for decades; its origin as domain-wall...journal article 2019
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Thomas, Miguel (author), Bossche, A. (author), Groen, W.A. (author), Bastemeijer, J. (author), Steijlen, A.S.M. (author), French, P.J. (author)Sweating is a normal reaction of the body to exercise. Although much of sweat is water, there are many other components. These components can be an indication of the condition of the athlete. Increase of elements and salts in the tissue will also work their way through to the sweat. Measurement directly in tissue can be an excellent indicator,...conference paper 2019
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Stuber, V.L. (author), Deutz, Daniella B. (author), Bennett, James (author), Cannel, David (author), de Leeuw, D.M. (author), van der Zwaag, S. (author), Groen, W.A. (author)Vibrational piezoelectric energy harvesters are being investigated to replace batteries in embedded sensor systems. The energy density that can be harvested depends on the figure of merit, d<sub>33</sub>g<sub>33</sub>, where d<sub>33</sub> and g<sub>33</sub> are the piezoelectric charge and voltage coefficient. Commonly used piezoelectric...journal article 2019
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Stuber, V.L. (author), Mahon, T.R. (author), van der Zwaag, S. (author), Groen, W.A. (author)Polymer-piezoceramic composites have drawn a lot of attention for sensor and energy harvesting applications. Poling such materials can be difficult due to the electric field getting mostly distributed over the low dielectric constant matrix. During this process, the electrical matrix conductivity plays a vital role. This work shows how two...journal article 2019
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Mahon, T.R. (author), Stuber, V.L. (author), Ammu, S.K. (author), van der Zwaag, S. (author), Groen, W.A. (author), Hoeks, T. (author), Guhathakurtha, S. (author)While most of the work on piezoelectric composites focuses on methods to reduce the dielectric constant of the composite (for better sensor and energy harvesting performance), for haptic feedback and actuator applications the opposite is desirable. We present here a study of the effect of adding a second ceramic phase (BaTiO3 nanoparticles)...conference paper 2019