Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Conference Object Citation - WoS: 3Citation - Scopus: 3Active Mixing Strategy With Electromechanical Platform for Lab-On Applications(Institute of Electrical and Electronics Engineers Inc., 2019) Karakuzu, Betül; Özçivici, Engin; Tekin, Hüseyin Cumhur; Tarım, E. AlperayThe main purpose of this study is to present a new active mixing strategy that can be used for lab-on-A-chip applications to shorten analysis time. An electromechanical platform composed of stepper and DC motors is designed and manufactured. This platform allows rapid mixing in microwells of a polydimethylsiloxane chip for analysis. Mixing in microwells is performed with a stirring bar spun automatically using the electromechanical platform. Mixing experiments performed at different spinning speeds and different time intervals on the platform. It was observed that mixing was achieved only in 300 ms inside 100 ?L microwell using 4300 revolutions per minute (rpm) spinning speeds. Hence, the proposed mixing strategy showed 200-fold faster mixing than pure diffusion-based mixing. © 2019 IEEE.Article Citation - WoS: 6Citation - Scopus: 6Fabrication of 3d Controlled in Vitro Microenvironments(Elsevier Ltd., 2014) Özdil, Berrin; Önal, Sevgi; Oruç, Tuğçe; Pesen Okvur, DevrimMicrofluidics-based lab-on-a-chips have many advantages, one of which is to provide physiologically relevant settings for cell biology experiments. Thus there is an ever increasing interest in their fabrication. Our goal is to construct three dimensional (3D) Controlled in vitro Microenvironments (CivMs) that mimic the in vivo microenvironments. Here, we present our optimized fabrication method that works for various lab-on-a-chip designs with a wide range of dimensions. The most crucial points are:While using one type of SU-8 photoresist (SU-2075), fine tuning of ramp, dwell time, spin speed, durations of soft bake, UV exposure and development allows fabrication of SU-8 masters with various heights from 40 to 600 μm.Molding PDMS (polydimethylsiloxane) at room temperature for at least two days instead of baking at higher temperatures prevents not only tears and bubbles in PDMS stamps but also cracks in the SU-8 master.3D nature of the CivMs is ensured by keeping the devices inverted during gel polymerization.Article Citation - WoS: 47Effect of Filler Amount on Thermoelastic Properties of Poly (dimethylsiloxane) Networks(Elsevier Ltd., 2005) Demir, Mustafa Muammer; Menceloğlu, Yusuf Z.; Erman, BurakEnd-linked poly(dimethylsiloxane) (PDMS) networks were prepared in the presence of fumed silica particles with hydroxyl groups at their surfaces. The silica particles were introduced into the polymer solution prior to end-linking. Hydroxyl ended PDMS chains were end-linked via the tetra functional crosslinker, tetraethoxysilane. The filler content varied in the range 0-5 wt%. Atomic Force Microscopy was used to image and characterize the silica particles. Swelling, stress-strain and thermoelasticity experiments were performed. The temperature coefficient and the energetic part of the force in uniaxial extension are found to increase with increasing silica amount. This observation is ascribed to effects contributed possibly by the adsorption layer around the silica particles.