Fabrication of microstructures on curved hydrogel substrates
Fabrication of microstructures on curved hydrogel substrates
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DOI：
10.1116/6.0002071
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发表时间：
2022-09
期刊：
影响因子：
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通讯作者：
M. Chen;X. Ding;L. Que;X. Liang
中科院分区：
文献类型：
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作者：
M. Chen;X. Ding;L. Que;X. Liang
新兴的可穿戴设备在生物医学和医疗保健领域非常有吸引力和前景，因为它们具有生物相容性，可用于监测原位生物标志物相关信号和外部刺激。许多这样的装置或系统需要在弯曲且柔性的水凝胶基底上制造的微型传感器。然而，在这样的衬底上制造微结构仍然具有挑战性，因为传统的平面光刻工艺与弯曲的、柔性的和水合的衬底不兼容。在这里，我们提出了一种阴影掩模辅助沉积工艺，能够直接产生金属微结构上的弯曲的水凝胶基板，特别是接触透镜，最流行的水凝胶基板可穿戴生物医学应用之一。在该过程中，弯曲的水凝胶基底在平坦表面上暂时变平，并且金属特征通过荫罩沉积在该基底上。为了实现高的图案化保真度，我们已经通过实验和理论研究了由于3D打印的样品保持器上的褶皱引起的各种类型的变形、由于平坦化过程引起的基底的几何变形以及在接触透镜的脱水和水合过程期间水凝胶材料的体积变化。使用这种方法，我们已经证明了制造各种钛图案阵列的接触镜具有高保真度和产量。
Emerging wearable devices are very attractive and promising in biomedical and healthcare fields because of their biocompatibility for monitoring in situ biomarker-associated signals and external stimulus. Many such devices or systems demand microscale sensors fabricated on curved and flexible hydrogel substrates. However, fabrication of microstructures on such substrates is still challenging because the traditional planar lithography process is not compatible with curved, flexible, and hydrated substrates. Here, we present a shadow-mask-assisted deposition process capable of directly generating metallic microstructures on the curved hydrogel substrate, specifically the contact lens, one of the most popular hydrogel substrates for wearable biomedical applications. In this process, the curved hydrogel substrate is temporarily flattened on a planar surface and metal features are deposited on this substrate through a shadow mask. To achieve a high patterning fidelity, we have experimentally and theoretically investigated various types of distortion due to wrinkles on 3D-printed sample holders, geometric distortion of the substrate due to the flattening process, and volume change of the hydrogel material during the dehydration and hydration processes of the contact lens. Using this method, we have demonstrated fabrication of various titanium pattern arrays on contact lenses with high fidelity and yield.