Presentation Information
[15p-PB1-43]Microscale Droplet Manipulation Using Magnetic Forces
〇Atsuki Niitsu1, Yasuhiro Ikezoe1 (1.NIT)
Keywords:
magnetic levitation
In recent years, we have successfully developed a diamagnetic levitation device capable of levitating diamagnetic materials such as water using permanent magnets [1]. In this device, water droplets with diameters of approximately 0.3 mm can be readily levitated in a narrow, elongated gap formed near the edges of a pair of rectangular permanent magnets. This technique is expected to be applicable to a wide range of studies, including materials science and protein crystal growth. In the current setup, water droplets generated by a humidifier are collected and levitated; however, to further broaden the scope of applications, it is desirable to develop a system in which water droplets can be directly transferred into the levitation region using experimental tools such as a micropipette.
However, the surface tension that supports a liquid droplet is very large, and even when a thin capillary with a diameter of approximately 50 μm is used, a water droplet does not detach under gravity until its diameter exceeds about 1.3 mm. Under the present conditions, levitating such a large droplet is difficult. Therefore, inspired by the work of Sakihama et al. [2], we investigated the use of magnetic force acting on water not only for levitation but also to assist in detaching a droplet from the tip of a capillary. Based on this concept, we aimed to construct a system capable of detaching droplets with diameters of approximately 0.5 mm from the capillary tip.
[1] T. Naito, et al., Appl. Phys. Lett. 125, 264102 (2024)
[2] T. Sakihama, et al., J. Magn. Soc. Jpn. Vol. 21 (4-2), 765-768 (1997)
However, the surface tension that supports a liquid droplet is very large, and even when a thin capillary with a diameter of approximately 50 μm is used, a water droplet does not detach under gravity until its diameter exceeds about 1.3 mm. Under the present conditions, levitating such a large droplet is difficult. Therefore, inspired by the work of Sakihama et al. [2], we investigated the use of magnetic force acting on water not only for levitation but also to assist in detaching a droplet from the tip of a capillary. Based on this concept, we aimed to construct a system capable of detaching droplets with diameters of approximately 0.5 mm from the capillary tip.
[1] T. Naito, et al., Appl. Phys. Lett. 125, 264102 (2024)
[2] T. Sakihama, et al., J. Magn. Soc. Jpn. Vol. 21 (4-2), 765-768 (1997)