Person: ŞİŞMAN, ALPER
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ŞİŞMAN
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ALPER
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Publication Metadata only A novel numerical model to simulate acoustofluidic particle manipulation(IOP PUBLISHING LTD, 2020) ŞİŞMAN, ALPER; Yazdani, Ali Mohammad; Sisman, AlperAcoustofluidic systems are attracting more attention in recent years because of their specifications, like versatility, high biocompatibility, high controllability, and simple design. However it is important to optimize the system parameters, which affects system performance. Simulation techniques have a crucial role in optimization since high fabrication costs limit the number of runs. However, the complex Multiphysics structure of the system makes the optimization process very elaborate. Here, an innovative and feasible numerical method to simulate and optimize the acoustofluidic particle manipulation process is reported. The proposed numerical method consists of three main steps. In the first step, surface acoustic waves are generated and propagated on a piezoelectric substrate. Next, the particle motion under the effect of the acoustophoresis force is simulated using successive two-dimensional models representing the different regions along the microfluidic channel. Finally, the particle trajectory is calculated using the superposition method. The proposed numerical method was validated using a reference experimental study available in the literature. The proposed method successfully simulated the separation of particles with diameters of 10 and 15 mu m. This numerical method can be used as an optimization tool for acoustofluidic particle manipulation systems.Publication Open Access Developing a surface acoustic wave-induced microfluidic cell lysis device for point-of-care DNA amplification(2023-01-01) ŞİŞMAN, ALPER; HUSSEINI A. A., Yazdani A. M., Ghadiri F., ŞİŞMAN A.We developed a microchip device using surface acoustic waves (SAW) and sharp-edge glass microparticles to rapidly lyse low-level cell samples. This microchip features a 13-finger pair interdigital transducer (IDT) with a 30-degree focused angle, creating high-intensity acoustic beams converging 6 mm away at a 16 MHz frequency. Cell lysis is achieved through centrifugal forces acting on Candida albicans cells and glass particles within the focal area. To optimize this SAW-induced streaming, we conducted 42 pilot experiments, varying electrical power, droplet volume, glass particle size, concentration, and lysis time, resulting in optimal conditions: an electrical signal of 2.5 W, a 20 μL sample volume, glass particle size below 10 μm, concentration of 0.2 μg, and a 5-min lysis period. We successfully amplified DNA target fragments directly from the lysate, demonstrating an efficient microchip-based cell lysis method. When combined with an isothermal amplification technique, this technology holds promise for rapid point-of-care (POC) applications.Publication Open Access Numerical and Experimental Studies on the Effect of Surface Roughness and Ultrasonic Frequency on Bubble Dynamics in Acoustic Cavitation(2020-03-03) ŞİŞMAN, ALPER; Altay, Rana; Sadaghiani, Abdolali K.; Sevgen, M. Ilker; Şişman, Alper; Koşar, AliWith many emerging applications such as chemical reactions and ultrasound therapy, acoustic cavitation plays a vital role in having improved energy efficiency. For example, acoustic cavitation results in substantial enhancement in the rates of various chemical reactions. In this regard, an applied acoustic field within a medium generates acoustic streaming, where cavitation bubbles appear due to preexisting dissolved gas in the working fluid. Upon cavitation inception, bubbles can undergo subsequent growth and collapse. During the last decade, the studies on the effects of different parameters on acoustic cavitation such as applied ultrasound frequency and power have been conducted. The bubble growth and collapse mechanisms and their distribution within the medium have been classified. Yet, more research is necessary to understand the complex mechanism of multi-bubble behavior under an applied acoustic field. Various parameters affecting acoustic cavitation such as surface roughness of the acoustic generator should be investigated in more detail in this regard. In this study, single bubble lifetime, bubble size and multi-bubble dynamics were investigated by changing the applied ultrasonic field. The effect of surface roughness on bubble dynamics was presented. In the analysis, images from a high-speed camera and fast video recording techniques were used. Numerical simulations were also done to investigate the effect of acoustic field frequency on bubble dynamics. Bubble cluster behavior and required minimum bubble size to be affected by the acoustic field were obtained. Numerical results suggested that bubbles with sizes of 50 µm or more could be aligned according to the radiation potential map, whereas bubbles with sizes smaller than 10 µm were not affected by the acoustic field. Furthermore, it was empirically proven that surface roughness has a significant effect on acoustic cavitation phenomena.