Japan Science & Technology Agency (JST), PRESTO, Department of Mechanical Science & Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8603, Aichi-ken, Japan.
Biomed Microdevices. 2010 Aug;12(4):745-52. doi: 10.1007/s10544-010-9428-z.
This paper describes a novel powerful noncontact actuation of a magnetically driven microtool (MMT), achieved by magnetization of the MMT and focusing of the magnetic field in a microfluidic chip for particle sorting. The following are the highlights of this study: (1) an MMT was successfully fabricated from a mixture of neodymium powder and polydimethylsiloxane; the MMT was magnetized such that it acted as an elastic micromagnet with a magnetic flux density that increased by about 100 times after magnetization, and (2) a pair of sharp magnetic needles was fabricated adjacent to a microchannel in a chip by electroplating, in order to focus the magnetic flux density generated by the electromagnetic coils below the biochip; these needles contribute to miniaturization of an actuation module that would enable the integration of multiple functions in the limited area of a chip. FEM analysis of the magnetic flux density around the MMT showed that the magnetic flux density in the setup with the magnetic needles was around 8 times better than that in the setup without the needles. By magnetization, the drive frequency of the MMT improved by about 10 times--from 18 Hz to 180 Hz. We successfully demonstrated the separation of copolymer beads of a particular size in a chip by image sensing.
本文描述了一种新颖的、强大的磁驱动微工具（MMT）非接触式驱动方法，通过在微流控芯片中对 MMT 进行磁化并聚焦磁场来实现粒子分选。本研究的主要亮点包括：（1）成功地用钕粉和聚二甲基硅氧烷混合物制造了一个 MMT；对 MMT 进行磁化，使它成为一个弹性微磁体，磁化后磁通量密度增加了约 100 倍；（2）通过电镀在芯片中的微通道旁边制造了一对尖锐的磁性针，以聚焦电磁线圈在生物芯片下方产生的磁通密度；这些针有助于使致动模块小型化，从而能够在芯片有限的区域内集成多个功能。对 MMT 周围磁通密度的有限元分析表明，带有磁针的设置中的磁通密度比没有磁针的设置好约 8 倍。通过磁化，MMT 的驱动频率提高了约 10 倍，从 18Hz 提高到 180Hz。我们通过图像感应成功地演示了在芯片中对特定尺寸的共聚物珠进行分离。
