Li Jing 

Associate Professor

China-UK Low Carbon College Shanghai Jiao Tong University 

Email: jingli76@sjtu.edu.cn

Dr. Li Jing received her Ph.D degree in Mechanical Engineering from City University of Hong Kong in 2018, after which she worked as a postdoc researcher in University of Pennsylvania. Since December 2021, she has joined China-UK Low Carbon College, Shanghai Jiao Tong University as an Associate Professor. Dr. Li’s research is to develop multidimensional materials with tailored interfacial properties, and explore how the triple-phase interfacial interactions coupled with multiple physical fields promote the dynamics of droplets for efficient energy harvesting and green transport. She has published many papers in leading journals, including Nature Physics, Nature Communications, Advanced Materials and so on. She has also received many prestigious awards, such as Materials Research Society (MRS) Graduate Student Gold Award (2016, Fall), Hiwin Doctoral Dissertation Silver Award (2019), Hong Kong Young Scientist Award (2020) and soon.

Title：Aerodynamics-assisted, efficient and scalable kirigami fog collectors

Abstract：Water shortage not only occurs in arid regions, but also in humid regions with little precipitation despite an abundance of suspended tiny fog droplets in environments [1-2]. Gravity-assisted mesh structures have been implemented to harvest fog droplets [3]. However, their efficiency is low due to the aerodynamic drag of fog-laden wind deflected around the mesh wires. Strategies such as the introduction of asymmetric structure shapes, optimization of surface roughness/chemistry and impregnation of lubricants can increase collection efficiency by promoting droplet-substrate (interfacial) interactions [4]. But their fabrication is complex and the resulting structures are often fragile and not scalable for outdoor settings. Here, we show that the three-dimensional and centimetric kirigami structures can control the wind flow, forming quasi-stable counter- rotating vortices[5]. The vortices regulate the trajectories of incoming fog clusters and eject extensive droplets to the substrate. As the characteristic structural length is increased to the size of vortices, we greatly reduce the dependence of fog collection on the structural delicacy. Together with gravity-directed gathering by the folds, the kirigami fog collector yields a collection efficiency of 16.1% at a low wind speed of 0.8 m/s and is robust against surface characteristics. The collection efficiency is maintained even on a 1 m2 collector in an outdoor setting.

Reference

[1]Zhai, L. et al. Patterned superhydrophobic surfaces: toward a synthetic mimic of the Namib Desert beetle. Nano Lett. 6, 1213-1217 (2006).

[2]LaPotin, A., Kim, H., Rao, S. R. & Wang, E. N. Adsorption-based atmospheric water harvesting: Impact of material and component properties on system-level performance. Acc. Chem. Res. 52, 1588-1597 (2019).

[3]Park, K.-C., Chhatre, S. S., Srinivasan, S., Cohen, R. E. & McKinley, G. H. Optimal design of permeable fiber network structures for fog harvesting. Langmuir 29, 13269-13277 (2013).

[4]Li, J., Li, J., Sun, J., Feng, S., & Wang, Z. Biological and engineered topological droplet rectifiers. Adv. Mater., 31, 1806501(2019).

[5]Li, J., Ran, R., Wang, H., Wang, Y., Chen, Y., Niu, S., Arratia, P.E. & Yang, S. Aerodynamics- assisted, efficient and scalable kirigami fog collectors. Nat. Commun. 12, 5484 (2021).