IEM Distinguished Lecturers Seminar: Leveraging Microfluidic devices to Emerging Technology & New Opportunity
*** Drinks and pizza at 11:45 in the lobby of BM 5202 ***
Abstract
Microfluidic technology has advanced significantly in recent years, enabling precise manipulation of biological molecules and nanomaterials for various applications. This talk will review two key studies that demonstrate the potential of microfluidic-based techniques in the fields of biophysics and quantum sensing. The first study focuses on the real-time observation of dynamic twisting motions in single KcsA potassium channels using Diffracted X-ray Tracking (DXT) combined with microfluidic technology. A gold nanocrystal is chemically attached to one end of the protein, which is anchored to a silicon nitride (SiN) membrane, allowing motion tracking by X-ray diffraction. Using a microfluidic device for rapid and precise exchange of neutral and acidic pH solutions, we observed cyclic pH-induced twisting motions in real time. This technique allows direct comparison of activation and reversal dynamics within the same molecule, providing valuable insight into ion channel gating mechanisms.
The second study highlights the use of fluorescent nanodiamonds (FNDs) containing nitrogen vacancy centers (NVCs) as highly sensitive thermometers. To improve the signal-to-noise ratio (SNR) for temperature mapping applications, we developed a microfluidics-guided assembly method that enables the formation of vertically aggregated FND clusters on a substrate. This technique enhances fluorescence signal intensity by superimposing emissions from individual FNDs, thereby improving temperature mapping accuracy. The resulting highly sensitive FND thermometers hold promise for a variety of applications, including electronic device monitoring, and biological systems.
These studies show how important microfluidics is for making new discoveries in science. By combining microfluidics with new technologies, we can find new uses for it in many different
scientific areas.
References
1. Yusuke Asagoe et al., “Diffracted X-Ray Tracking Method for Analyzing the Sequential Dynamic Motion of Ion Channels in Response to a Chemical Stimulus”, The 28th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2024), Montreal, Canada (October, 2024), W246.k
2. Keita Saikawa et al., “Microfluidics-Guided Fluorescent Nanodiamond Assembly Method for Highly Sensitive Thermometry”, Sens. Actuator A-Phys. 386 (2025), 116312 https://doi.org/10.1016/j.sna.2025.116312
Bio
Yoshikazu Hirai received the Ph.D. degree from Kyoto University, Japan, in 2007. He was an Assistant Professor with the Department of Micro Engineering, Kyoto University, in 2013. Since 2021, he has been a Junior Associate Professor with the Department of Mechanical Engineering and Science, Kyoto University. His current research interests include fabrication and packaging for generic MEMS/NEMS, silicon/polymer-based MEMS devices and systems, atomic MEMS devices, and micro/nanofluidic systems for microphysiological systems. He has received several academic awards such as the Institute of Electrical Engineers of Japan (IEEJ) Distinguished Paper Award in 2017. He is an Associate Editor of IEEE Transactions on Nanotechnology, an Editorial Board Member of Sensors and Actuators Reports, and a MEMS Technical Committee Member of IEEE Electron Devices Society (EDS).
Abstract
Microfluidic technology has advanced significantly in recent years, enabling precise manipulation of biological molecules and nanomaterials for various applications. This talk will review two key studies that demonstrate the potential of microfluidic-based techniques in the fields of biophysics and quantum sensing. The first study focuses on the real-time observation of dynamic twisting motions in single KcsA potassium channels using Diffracted X-ray Tracking (DXT) combined with microfluidic technology. A gold nanocrystal is chemically attached to one end of the protein, which is anchored to a silicon nitride (SiN) membrane, allowing motion tracking by X-ray diffraction. Using a microfluidic device for rapid and precise exchange of neutral and acidic pH solutions, we observed cyclic pH-induced twisting motions in real time. This technique allows direct comparison of activation and reversal dynamics within the same molecule, providing valuable insight into ion channel gating mechanisms.
The second study highlights the use of fluorescent nanodiamonds (FNDs) containing nitrogen vacancy centers (NVCs) as highly sensitive thermometers. To improve the signal-to-noise ratio (SNR) for temperature mapping applications, we developed a microfluidics-guided assembly method that enables the formation of vertically aggregated FND clusters on a substrate. This technique enhances fluorescence signal intensity by superimposing emissions from individual FNDs, thereby improving temperature mapping accuracy. The resulting highly sensitive FND thermometers hold promise for a variety of applications, including electronic device monitoring, and biological systems.
These studies show how important microfluidics is for making new discoveries in science. By combining microfluidics with new technologies, we can find new uses for it in many different
scientific areas.
References
1. Yusuke Asagoe et al., “Diffracted X-Ray Tracking Method for Analyzing the Sequential Dynamic Motion of Ion Channels in Response to a Chemical Stimulus”, The 28th International Conference on Miniaturized Systems for Chemistry and Life Sciences (MicroTAS 2024), Montreal, Canada (October, 2024), W246.k
2. Keita Saikawa et al., “Microfluidics-Guided Fluorescent Nanodiamond Assembly Method for Highly Sensitive Thermometry”, Sens. Actuator A-Phys. 386 (2025), 116312 https://doi.org/10.1016/j.sna.2025.116312
Bio
Yoshikazu Hirai received the Ph.D. degree from Kyoto University, Japan, in 2007. He was an Assistant Professor with the Department of Micro Engineering, Kyoto University, in 2013. Since 2021, he has been a Junior Associate Professor with the Department of Mechanical Engineering and Science, Kyoto University. His current research interests include fabrication and packaging for generic MEMS/NEMS, silicon/polymer-based MEMS devices and systems, atomic MEMS devices, and micro/nanofluidic systems for microphysiological systems. He has received several academic awards such as the Institute of Electrical Engineers of Japan (IEEJ) Distinguished Paper Award in 2017. He is an Associate Editor of IEEE Transactions on Nanotechnology, an Editorial Board Member of Sensors and Actuators Reports, and a MEMS Technical Committee Member of IEEE Electron Devices Society (EDS).
Practical information
- General public
- Free