Laser-Induced Superhydrophobic Polymer Surface for Droplet Manipulation, Controllable Light-Driven Actuator, and Underwater Motion Monitoring

In the field of smart materials, there is a demand to fabricate surfaces with superhydrophobic and conductive features in a cost-effective and efficient fabrication manner. In this study, a high-efficiency approach for fabricating superhydrophobic and multifunctional surfaces is presented. By using a cost-effective fiber laser and ablating the PDMS/CNT nanocomposite surface, superhydrophobic (WCA = 157°, SA = 7.35°) unidirectional groove structures were fabricated with a high efficiency of 3.5 s/cm² under a laser spacing of 75 μm and a scanning speed of 500 mm/s. Three separate application scenarios for superhydrophobic PDMS/CNT nanocomposite are demonstrated. The results showed that the superhydrophobic PDMS/CNT nanocomposite facilitated nondestructive droplet transfer and enabled fluid manipulation via self-floating. Its load-bearing capacity was increased by 49.8%. The movement of the PDMS/CNT nanocomposite on water was accelerated by 116% after laser irradiation, and it achieved optically controllable motion of complex paths as light-driven actuators. Notably, they maintained exceptional superhydrophobic properties, even when stretched to a strain of 75%. PDMS/CNT nanocomposite can effectively monitor various underwater motion signals such as underwater finger flexion, wrist flexion, and fist clenching, which exhibited great potential application in underwater sensor monitoring.