A microstructured silicon membrane with entrapped hydrogels for environmentally sensitive fluid gating
A microstructured silicon membrane with entrapped hydrogels for environmentally sensitive fluid gating
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DOI：
10.1016/j.snb.2005.04.020
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发表时间：
2006-03-30
影响因子：
8.4
通讯作者：
Ziaie, B
中科院分区：
文献类型：
--
作者：
Baldi, A;Lei, M;Ziaie, B
在本文中，我们报告了一种新的水凝胶微阀的制作和表征。基本结构是具有孔阵列的硅膜，所述孔阵列具有设计成锚水凝胶同时允许其门控穿过膜的流动的内部结构。每个孔（直径140 μ m）有一个中心柱，由膜两侧的四根系绳悬挂。刺激敏感性水凝胶在每个孔内聚合。在溶胀状态下，水凝胶完全占据孔口的空隙空间，完全阻断压力驱动的流体流动。在收缩状态下，水凝胶围绕柱收缩，允许流体流过开放的环形间隙。微结构化硅膜的制造仅需要两个掩模步骤，并且涉及深沟槽和KOH蚀刻的组合。两种不同的水凝胶，基于N-异丙基丙烯酰胺（温度敏感）和苯基硼酸（pH值和葡萄糖敏感）被困在这个微阀和测试。测量的响应时间为10 s（温度）、4 min（pH）和10 min（葡萄糖）。对于温度敏感性和（pH/葡萄糖）敏感性水凝胶，微阀在水凝胶破裂之前可以承受的最大压降分别为21 kPa和16 kPa。(c)2005 Elsevier B. V.保留所有权利。
In this paper, we report on the fabrication and characterization of anew hydrogel-based microvalve. The basic structure is a silicon membrane having an array of orifices with an internal structure designed to anchor the hydrogel while allowing it to gate the flow across the membrane. Each orifice (140 mu m diameter) has a central post suspended by four tethers on each side of the membrane. A stimuli-sensitive hydrogel is polymerized inside each orifice. In the swollen state, the hydrogel completely occupies the void space of the orifice, completely blocking pressure-driven fluid flow. In the shrunken state, the hydrogel contracts around the post, allowing fluid to flow through an opened annular gap. Fabrication of the microstructured silicon membrane requires only two masking steps and involves a combination of deep trench and KOH etch. Two different hydrogels, based on N-isopropylacrylamide (temperature-sensitive) and phenylboronic acid (pH and glucose-sensitive) were trapped and tested in this microvalve. The measured response times were 10 s (temperature), 4 min (pH), and 10 min (glucose). The maximum pressure drop the microvalve can sustain before breakage of the hydrogel is 21 kPa and 16 kPa for temperature-sensitive and (pH/glucose)-sensitive hydrogels, respectively. (c) 2005 Elsevier B.V. All rights reserved.