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Bui, T.H. (author), Nguyen, V.C. (author), Vollebregt, S. (author), Morana, B. (author), van Zeijl, H.W. (author), Chu Duc, Trinh (author), Sarro, Pasqualina M (author)The effect of the contact angle and radius of a microsize droplet on the surface acoustic wave (SAW) response for microfluidic applications is reported. It is studied through the dynamic change of the droplet shape during the evaporation process. An aluminium nitride SAW device, operating at 125.7 MHz, is utilized to investigate the...journal article 2017
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Belardinelli, P. (author), Ghatkesar, M.K. (author), Staufer, U. (author), Alijani, F. (author)Linear and non-linear vibrations of a U-shaped hollow microcantilever beam filled with fluid and interacting with a small particle are investigated. The microfluidic device is assumed to be subjected to internal flowing fluid carrying a buoyant mass. The equations of motion are derived via extended Hamilton's principle and by using Euler...journal article 2017
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Vleugel, M. (author), Roth, S.C.A. (author), Groenendijk, Celebrity F. (author), Dogterom, A.M. (author)Mitotic spindle assembly, positioning and orientation depend on the combined forces generated by microtubule dynamics, microtubule motor proteins and cross-linkers. Growing microtubules can generate pushing forces, while depolymerizing microtubules can convert the energy from microtubule shrinkage into pulling forces, when attached, for...journal article 2016
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Heeres, A.S. (author), Schroën, K. (author), Heijnen, J.J. (author), Van der Wielen, L.A.M. (author), Cuellar, M.C. (author)Developments in synthetic biology enabled the microbial production of long chain hydrocarbons, which can be used as advanced biofuels in aviation or transportation. Currently, these fuels are not economically competitive due to their production costs. The current process offers room for improvement: by utilizing lignocellulosic feedstock,...journal article 2015
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Pérez Garza, H. (author), Ghatkesar, M.K. (author), Basak, S. (author), Löthman, P. (author), Staufer, U. (author)To manipulate liquid matter at the nanometer scale, we have developed a robotic assembly equipped with a hollow atomic force microscope (AFM) cantilever that can handle femtolitre volumes of liquid. The assembly consists of four independent robots, each sugar cube sized with four degrees of freedom. All robots are placed on a single platform...journal article 2015
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Van Oorschot, R. (author), Perez Garza, H.H. (author), Derks, R.J.S. (author), Staufer, U. (author), Ghatkesar, M.K. (author)We present the development of a microfluidic AFM (atomic force microscope) cantilever-based platform to enable the local dispensing and aspiration of liquid with volumes in the pico-to-femtoliter range. The platform consists of a basic AFM measurement system, microfluidic AFM chip, fluidic interface, automated substrate alignment, external...journal article 2015
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Ghatkesar, M.K. (author), Perez Garza, H.H. (author), Heuck, F. (author), Staufer, U. (author)Advances in micro and nano fabrication technologies have enabled fabrication of smaller and more sensitive devices for applications not only in solid-state physics but also in medicine and biology. The demand for devices that can precisely transport material, specifically fluids are continuously increasing. Therefore, integration of various...journal article 2014
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Van Vliet, S. (author), Hol, F.J.H. (author), Weenink, T. (author), Galajda, P. (author), Keymer, J.E. (author)Background Bacterial habitats, such as soil and the gut, are structured at the micrometer scale. Important aspects of microbial life in such spatial ecosystems are migration and colonization. Here we explore the colonization of a structured ecosystem by two neutrally labeled strains of Escherichia coli. Using time-lapse microscopy we studied the...journal article 2014
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Moolman, M.C. (author), Huang, Z. (author), Krishnan, S.T. (author), Kerssemakers, J.W.J. (author), Dekker, N.H. (author)Background: Controlled restriction of cellular movement using microfluidics allows one to study individual cells to gain insight into aspects of their physiology and behaviour. For example, the use of micron-sized growth channels that confine individual Escherichia coli has yielded novel insights into cell growth and death. To extend this...journal article 2013
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Hoang, D.A. (author), Portela, L.M. (author), Kleijn, C.R. (author), Kreutzer, M.T. (author), Van Steijn, V. (author)The breakup of droplets due to creeping motion in a confined microchannel geometry is studied using three-dimensional numerical simulations. Analogously to unconfined droplets, there exist two distinct breakup phases: (i) a quasi-steady droplet deformation driven by the externally applied flow; and (ii) a surface-tension-driven three-dimensional...journal article 2013
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Männik, J. (author), Wu, F. (author), Hol, F.J.H. (author), Bisicchia, P. (author), Sherratt, D.J. (author), Keymer, J.E. (author), Dekker, C. (author)Cell division in typical rod-shaped bacteria such as Escherichia coli shows a remarkable plasticity in being able to adapt to a variety of irregular cell shapes. Here, we investigate the roles of the Min system and the nucleoid-occlusion factor SlmA in supporting this adaptation. We study “squeezed” E. coli in narrow nanofabricated channels...journal article 2012
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Geschiere, S.D. (author), Ziemecka, I. (author), Van Steijn, V. (author), Koper, G.J.M. (author), Van Esch, J.H. (author), Kreutzer, M.T. (author)This paper studies the Rayleigh-Plateau instability for co-flowing immiscible aqueous polymer solutions in a microfluidic channel. Careful vibration-free experiments with controlled actuation of the flow allowed direct measurement of the growth rate of this instability. Experiments for the well-known aqueous two phase system (ATPS, or aqueous...journal article 2012
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Galindo-Rosales, F.J. (author), Campo-Deano, L. (author), Pinho, F.T. (author), Van Bokhorst, E. (author), Hamersma, P.J. (author), Oliveira, M.S.N. (author), Alves, M.A. (author)In this study, two microfluidic devices are proposed as simplified 1-D microfluidic analogues of a porous medium. The objectives are twofold: firstly to assess the usefulness of the microchannels to mimic the porous medium in a controlled and simplified manner, and secondly to obtain a better insight about the flow characteristics of...journal article 2011
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Harry, K.J. (author), Strobel, S.. (author), Yang, J.K.W. (author), Duan, H. (author), Berggren, K.K. (author)In order to better characterize the development of the electron-beam resist hydrogen silsesquioxane (HSQ), the authors used a quartz crystal microbalance (QCM) to study its rate of dissolution in situ. The authors determined the effect of both salt concentration and applied electric potential on the development rate of HSQ. The development rates...journal article 2011
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Hussong, J. (author), Breugem, W.P. (author), Westerweel, J. (author)In this numerical study we investigate the flow induced by metachronal coordination between beating cilia arranged in a densely packed layer by means of a continuum model. The continuum approach allows us to treat the problem as two-dimensional as well as stationary, in a reference frame moving with the speed of the metachronal wave. The model...journal article 2011
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Heuck, F.C.A. (author), Staufer, U. (author)A low voltage electroosmotic (eo) pump suitable for high density integration into microfabricated fluidic systems has been developed. The high density integration of the eo pump required a small footprint as well as a specific on-chip design to ventilate the electrolyzed gases emerging at the platinum (Pt) electrodes. For this purpose, a novel...journal article 2011
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Weber, E. (author), Rosenauer, M. (author), Verhaert, P.D.E.M. (author), Vellekoop, M.J. (author)We present an optofluidic microsystem integrated onto a single device featuring on-chip light guiding and positioning under stable and low-loss conditions. Integration of optical components onto a microfluidic chip offers numerous new possibilities in the field of particle and cell analysis, but reconfigurable on-chip light positioning is still...journal article 2010
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Rosenauer, M. (author), Buchegger, W. (author), Finoulst, I. (author), Verhaert, P.D.E.M. (author), Vellekoop, M. (author)In this study, the design, realization and measurement results of a novel optofluidic system capable of performing absorbance-based flow cytometric analysis is presented. This miniaturized laboratory platform, fabricated using SU-8 on a silicon substrate, comprises integrated polymer-based waveguides for light guiding and a biconcave cylindrical...journal article 2010
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Malsch, D. (author), Gleichmann, N. (author), Kielpinski, M. (author), Mayer, G. (author), Henkel, T. (author), Mueller, D. (author), Van Steijn, V. (author), Kleijn, C. (author), Kreutzer, M.T. (author)We describe the formation of water in oil droplets, which are commonly used in lab-on-a-chip systems for sample generation and dosing, at microfluidic Tshaped nozzles from elastic feed lines. A narrow nozzle forms a barrier for a liquid–liquid interface, such that pressure can build up behind the nozzle up to a critical pressure. Above this...journal article