Kinetics of Light-Responsive CNT / PNIPAM Hydrogel Microactuators.
Kinetics of Light-Responsive CNT / PNIPAM Hydrogel Microactuators.
复制标题
DOI：
10.1002/smll.202305034
复制
发表时间：
2023-10
期刊：
影响因子：
13.3
通讯作者：
Aoife Gregg;Michael F. L. De Volder;J. Baumberg
中科院分区：
文献类型：
--
作者：
Aoife Gregg;Michael F. L. De Volder;J. Baumberg
研究了垂直排列的碳纳米管森林（CNT）与聚n -异丙基丙烯酰胺（PNIPAM）水凝胶复合材料组成的光响应微致动器。这种复合材料的优点是碳纳米管作为黑色吸收剂，有效地捕获辐射加热并触发PNIPAM收缩。此外，碳纳米管森林可以使用光刻技术精确地绘制出从几微米到几毫米大小的结构，这些碳纳米管- pnipam复合材料可以实现15毫秒的响应时间。通过对高速视频的详细分析，研究了这些微致动器的动力学。与热对流和聚合物扩散相结合的溶胀动力学理论模型进行了比较，表明聚合物扩散是该体系的限速因素。讨论了这种碳纳米管/水凝胶致动器作为微游泳器的应用，以光致动微水母设计为例，并演示了>1500次循环。
Light-responsive microactuators composed of vertically aligned carbon nanotube (CNT) forests mixed with poly(N-isopropylacrylamide) (PNIPAM) hydrogel composites are studied. The benefit of this composite is that CNTs act as a black absorber to efficiently capture radiative heating and trigger PNIPAM contraction. In addition, CNT forests can be patterned accurately using lithography to span structures ranging from a few micrometers to several millimeters in size, and these CNT-PNIPAM composites can achieve response times as fast as 15 ms. The kinetics of these microactuators are investigated through detailed analysis of high-speed videos. These are compared to a theoretical model for the deswelling dynamics, which combines thermal convection and polymer diffusion, and shows that polymer diffusion is the rate-limiting factor in this system. Applications of such CNT/hydrogel actuators as microswimmers are discussed, with light-actuating micro-jellyfish designs exemplified, and >1500 cycles demonstrated.