Self-aligned fabrication process for active membrane in magnetically driven micropump using photosensitive composite
Self-aligned fabrication process for active membrane in magnetically driven micropump using photosensitive composite
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DOI：
10.1088/1361-6439/ab6302
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发表时间：
2020-02-01
影响因子：
2.3
通讯作者：
Suzuki, Takaaki
中科院分区：
文献类型：
--
作者：
Nakahara, Tasuku;Ueda, Yusaku;Suzuki, Takaaki
在本文中，我们提出了一种使用光敏复合材料制造微泵用的活性膜的简单制造工艺。该复合材料是由负性光致抗蚀剂(SU-8)和磁性粒子的混合物制成的。我们评估了由Fe3O4、Ni或Fe制成的复合材料的磁化和吸引力。在本实验中，当Fe含量为50wt%时，复合材料的磁化强度和吸力最大，分别为300kAm(-1)和2.7mN。复合材料(Fe：50wt%)的加工性能表明，其饱和曝光厚度约为25微米，这是由于曝光过程中紫外光的透过率较低所致。我们用一种简单的工艺制作了微泵，该工艺包括利用上述复合材料的可加工性在一步自对准光刻工艺中同时制造活性薄膜和中空结构。制作的器件表明，随着外加磁场从10kA m(-1)增加到90kA m(-1)，膜的位移增加。当外加磁场为90kA m(-1)时，最大位移为4.2微米，频率为5赫兹。用粒子跟踪法对微泵的流量进行了估算，结果表明，在90 kA m(-1)、频率为5 Hz时，微泵的流量为36.1 nL min(-1)。
In this paper, we propose a simple fabrication process for an active membrane utilised in the manufacture of micropumps using a photosensitive composite. The composite is developed from a mixture of a negative photoresist (SU-8) and magnetic particles. We evaluated the magnetisation and attractive force of the composites made of Fe3O4, Ni, or Fe. In our experiment, the composite made of Fe (50 wt%) demonstrated the maximum values for magnetisation and attractive force, which were 300 kA m(-1) and 2.7 mN, respectively. The processability of the composite (Fe: 50 wt%) showed a saturated exposure thickness of approximately 25 mu m, which was caused by the low transmittance for ultraviolet light in the exposure process. We fabricated a micropump using a simple process, which included the manufacture of both of an active membrane and a hollow structure in a one-step self-aligned photolithography process using above processability of the composite. The fabricated device demonstrated that the displacement of the membrane increased with the increase in the applied magnetic field from 10 kA m(-1) to 90 kA m(-1). The maximum displacement was 4.2 mu m at 5 Hz in an applied magnetic field of 90 kA m(-1). The flow rate of the micropump was evaluated by particle tracking method and the result was 36.1 nl min(-1) at 5 Hz in 90 kA m(-1).