Gansu International Scientific and Technological Cooperation Base of Water-Retention Chemical Functional Materials, College of Chemistry and Chemical Engineering , Northwest Normal University , Lanzhou 730070 , China.
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics , Chinese Academy of Sciences , Lanzhou 730000 , China.
ACS Appl Mater Interfaces. 2019 Oct 2;11(39):36073-36080. doi: 10.1021/acsami.9b10885. Epub 2019 Sep 18.
The actuation phenomena of materials upon external stimulus have attracted much attention for the development of excellent sensors and devices. Herein, we present a smart Janus-faced film that exhibits novel behavior of reverse orthogonal actuation under high humidity and a positive actuation under low humidity, which is achieved by asymmetric polymer brushes on polydimethysiloxane as a substrate through surface-initiated atom transfer radical polymerization. The classical theory of plates and shells and finite element simulations are also applied to understand the orthogonal actuation mechanism of the actuator. This Janus-faced film can reversely grab objects rapidly under high humidity, which provides significant potential to design a more intelligent actuator. In addition, this film is highly sensitive to humidity that even the approaching finger can make it to bend, which is just like the actuation behavior of . Based on the above phenomena, we also design the sensing devices to realize the detection of humidity. Interestingly, the film intelligently identifies different solvents (e.g., water and ethanol). This work may demonstrate significant potential in smart surface modifications, flexible robots, bionic sensors, and other fields.
材料在外力刺激下的驱动现象引起了人们的广泛关注，因为这为开发优秀的传感器和器件提供了可能。在这里，我们展示了一种智能双面薄膜，它在高湿度下表现出新颖的反向正交驱动行为，在低湿度下表现出正向驱动行为，这是通过在聚二甲基硅氧烷基底上通过表面引发原子转移自由基聚合实现的不对称聚合物刷实现的。经典的板壳理论和有限元模拟也被应用于理解驱动器的正交驱动机制。这种双面薄膜在高湿度下可以快速反向抓取物体，这为设计更智能的驱动器提供了重要的潜力。此外，这种薄膜对湿度非常敏感，即使是接近的手指也能使它弯曲，这就像 的驱动行为一样。基于上述现象，我们还设计了感测器件来实现湿度的检测。有趣的是，该薄膜可以智能识别不同的溶剂（例如水和乙醇）。这项工作可能在智能表面改性、柔性机器人、仿生传感器等领域具有重要的应用潜力。
