Collecting water from fog flow is emerging as a promising solution to the water shortage problem. This work demonstrated a novel environmentally responsive water collector made from a self-prepared Janus polyvinyl alcohol sponge in combination with a two-way shape memory alloy spring, which transforms the traditional manner of static water collection into a dynamic one. The unidirectional water transport of the Janus structure together with the dynamic collection approach correspond to a 30.8% increase in the water-collection rate (WCR). The resultant WCR is up to 5.1 g/h, which ranks relatively high compared to similar studies. The light- and thermal-response capability, easy fabrication, and good cycling performance indicate that our devices could be utilized in a variety of applications. In this work, an efficient, intelligent adaptive, simple-preparation, precision-guided, and economical fog-collecting devices are recommended. Our work provides new insights on the design of high-efficient water collectors with practicability.
Keywords: Janus; fog harvesting; shape memory alloy; unidirectional transportation; water collection.