Browsing by Author "Erdoğan, R. Tufan"
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Item Open Access High resolution dielectric characterization of single cells and microparticles using integrated microfluidic microwave sensors(Institute of Electrical and Electronics Engineers, 2023-03-01) Seçme, Arda; Tefek, Uzay; Sarı, Burak; Pisheh, Hadi Sedaghat; Uslu, H. Dilara; Akbulut, Özge; Küçükoğlu, Berk; Erdoğan, R. Tufan; Alhmoud, Hashim; Şahin, Özgür; Hanay, M. SelimMicrowave sensors can probe intrinsic material properties of analytes in a microfluidic channel at physiologically relevant ion concentrations. While microwave sensors have been used to detect single cells and microparticles in earlier studies, the synergistic use and comparative analysis of microwave sensors with optical microscopy for material classification and size tracking applications have been scarcely investigated so far. Here we combined microwave and optical sensing to differentiate microscale objects based on their dielectric properties. We designed and fabricated two types of planar sensor: a Coplanar Waveguide Resonator (CPW) and a Split-Ring Resonator (SRR). Both sensors possessed sensing electrodes with a narrow gap to detect single cells passing through a microfluidic channel integrated on the same chip. We also show that standalone microwave sensors can track the relative changes in cellular size in real-time. In sensing single 20-micron diameter polystyrene particles, Signal-to-Noise ratio values of approximately 100 for CPW and 70 for SRR sensors were obtained. These findings demonstrate that microwave sensing technology can serve as a complementary technique for single-cell biophysical experiments and microscale pollutant screening.Item Open Access Microfluidics-integrated microwave sensors for single cells size discrimination(Institute of Electrical and Electronics Engineers, 2021-04-01) Seçme, Arda; Pisheh, Hadi Sedaghat; Uslu, H. Dilara; Akbulut, Özge; Erdoğan, R. Tufan; Hanay, M. SelimThe size of a cell is one of the most fundamental biophysical parameters it possesses. Traditionally size measurements are done by using optical microscopy and quantitative phase imaging. However, a sensor with higher resolution, high throughput and lower cost is still needed. Here, a novel microfluidics-integrated microwave sensor is demonstrated to characterize single cells in real-time without labelling. Coplanar waveguide resonator is designed with a bowtie-shaped sensing electrodes separated by 50 μm. Cells are transported to sensing region by microfluidic channels and their sizes are measured simultaneously by the microwave sensors and optical microscopy. To enhance the microwave resolution, the microwave resonator is equipped with external heterodyne measurement circuitry detecting each and every cell passing through the sensing region. By comparing quantitative microscopic image analysis with frequency shifts, we show that microwave sensors can effectively measure cellular size. Our results indicate that microfluidics-integrated microwave sensors (MIMS) can be used for detecting.Item Open Access Microfluidics-integrated microwave sensors for single cells size discrimination(Institute of Electrical and Electronics Engineers, 2021-04) Seçme, Arda; Pisheh, Hadi Sedaghat; Uslu, H. Dilara; Akbulut, Özge; Erdoğan, R. Tufan; Hanay, Mehmet SelimThe size of a cell is one of the most fundamental biophysical parameters it possesses. Traditionally size measurements are done by using optical microscopy and quantitative phase imaging. However, a sensor with higher resolution, high throughput and lower cost is still needed. Here, a novel microfluidics-integrated microwave sensor is demonstrated to characterize single cells in real-time without labelling. Coplanar waveguide resonator is designed with a bowtie-shaped sensing electrodes separated by 50 μm. Cells are transported to sensing region by microfluidic channels and their sizes are measured simultaneously by the microwave sensors and optical microscopy. To enhance the microwave resolution, the microwave resonator is equipped with external heterodyne measurement circuitry detecting each and every cell passing through the sensing region. By comparing quantitative microscopic image analysis with frequency shifts, we show that microwave sensors can effectively measure cellular size. Our results indicate that microfluidics-integrated microwave sensors (MIMS) can be used for detecting.