Nanopattern Fabrication of Gold on Hydrogels and Application to Tunable Photonic Crystal
Nanopattern Fabrication of Gold on Hydrogels and Application to Tunable Photonic Crystal
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DOI：
10.1002/adma.201201522
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发表时间：
2012-10-02
影响因子：
29.4
通讯作者：
Osada, Yoshihito
中科院分区：
文献类型：
--
作者：
Shimamoto, Naonobu;Tanaka, Yoshito;Osada, Yoshihito
聚合物水凝胶由一个充满水的弹性交联型聚合物网络组成，使水凝胶具有粘弹性。[1，2]水凝胶的一个特殊特征是，凝胶的膨胀状态可以通过环境变化(包括pH、离子种类、离子浓度和温度)以及通过物理刺激(如紫外线和电磁场)来调节。这使得能够动态控制凝胶的膨胀和收缩，以及液体或溶质的渗透，[2，3]，并能够将凝胶应用于刺激响应性软、湿物质，包括人工肌肉、[4，5]软致动器、药物输送系统、[6]和渗透选择性膜。[6]电驱动人造肌肉、[7，8]磁响应致动器、[9]温控形状记忆凝胶、[10]和药物输送系统。这些化学机械现象作为一种机械换能器，伴随着凝胶中的物理化学离子传输或电化学反应。然而，研究人员缺乏技术来监测凝胶的物理化学过程，并能够对化学机械行为进行精确的原位时间过程测量。一种能够在纳米尺度上检测形状变化动力学的新的实验方法将有助于我们了解凝胶的物理化学行为，并可能推动纳米凝胶科学的进步，包括基于离子的生物传感器件的开发。关键的困难在于制造用于在凝胶上传感的金属图案。由于水凝胶的水分含量往往是聚合物网络重量的数倍，而且它是高度动态的物质，具有很大的波动，因此不可能使用传统的纳米级器件制造技术。
A polymer hydrogel consists of an elastic cross-linked polymer network with water filling the interstitial spaces, giving hydrogels viscoelastic properties.[1, 2] One specific hydrogel characteristic is that the gel swelling state can be modulated through environmental changes, including pH, ionic species, ionic concentration, and temperature, and through physical stimuli such as UV light and electromagnetic fields. This enables dynamic control of the gel expansion and contraction, and of the permeation of fluids or solutes,[2, 3] and enables gel applications as stimuli-responsive soft, wet matter, including artificial muscles,[4, 5] soft actuators, drug delivery systems,[6] and permselective membranes.[6] Electro-driven artificial muscles,[7, 8] magneticallyresponsive actuators,[9] temperature controlled shape memory gels,[10] and drug delivery systems.[11] are examples of these soft, wet gel devices. These chemomechanical phenomena, which act as a type of mechanical transducer, are accompanied by physico-chemical ion transportation or electrochemical reactions in the gel.However, researchers have lacked techniques to monitor the gel’s physico-chemical processes and enable precise insitu time-course measurement of chemomechanical behavior. A novel experimental method enabling nanoscale detection of the shape change dynamics would help us understand the gel’s physico-chemical behavior, and could lead to advances in nanoscale gel science, including ion-based bio-sensing device development. The critical difficulty lies in fabrication of metallic patterns for sensing on the gels. Because hydrogel water content is often many times the weight of the polymer network, and because it is highly dynamic matter with substantial fluctuation, it is impossible to use conventional nano-scale device fabrication techniques.