Photopatterning of thermally sensitive hydrogels useful for microactuators
Photopatterning of thermally sensitive hydrogels useful for microactuators
复制标题
DOI：
10.1016/s0924-4247(99)00080-1
复制
发表时间：
1999-10-12
影响因子：
4.6
通讯作者：
Fischer, WJ
中科院分区：
文献类型：
--
作者：
Hoffmann, J;Plötner, M;Fischer, WJ
基于 PNIPAAm [聚（N-异丙基丙烯酰胺）] 的水凝胶对于微执行器来说是一种有吸引力的工作材料，因为它们会因热诱导相变而膨胀，从而导致非常高的体积膨胀。通过与发色团共聚，开发了一种专门设计的聚合物，可以光交联成凝胶并通过这种光图案化。这项工作的重点是使用这种共聚物制备微图案并对其进行表征。光化学反应的效率相当好，并且已经实现了小至20μm香料的图案化结果。与基于PNIPAAm的块状凝胶相比，Si/SiO2基底上的点状图案水凝胶薄膜在水中的溶胀具有相似的温度依赖性，并且溶胀比为3至3.5，与本体PNIPAAm基凝胶处于相同的数量级，但在凝胶点处测量的2至8秒的转变时间比宏观物体的转变时间短得多，使得该材料对于微致动器性能感兴趣。转变温度从纯 PNIPAAm 的 32 至 34 摄氏度降至共聚物光图案化凝胶的 18 至 20 摄氏度。 (C) 1999 Elsevier Science S.A. 保留所有权利。
Hydrogels based on PNIPAAm [poly-(N-isopropylacrylamide)] are an attractive working material for microactuators because of their swelling with thermally induced phase transitions leading to a very high volume expansion. By the employment of co-polymerization with a chromophore, a specially designed polymer has been developed that can be photocrosslinked to a gel and by this photopatterned. The focal point of this work is the preparation and characterization of mircopattems using this co-polymer. The efficiency of the photochemical reaction is quite good and patterning results down to 20 mu m spices have been achieved. The swelling of dot-like patterned hydrogel films on Si/SiO2 substrates in water occurs with similar temperature dependency and a swelling ratio of 3 to 3.5 in the same order of magnitude compared to bulk PNIPAAm-based gels, but the transition time of 2 to 8 s measured at the gelous dots is much shorter than that of macroscopic objects, making the material interesting for microactuator performance. The transition temperature decreases from 32 to 34 degrees C at pure PNIPAAm to 18 to 20 degrees C at the photopatterned gels of the copolymer. (C) 1999 Elsevier Science S.A. All rights reserved.