In fields such as advanced manufacturing, surface science, and interfacial mechanics, smart flexible surfaces offer distinct advantages over traditional surfaces — they are covered with hair-like cilia that can be manipulated by external fields (e.g., magnetic fields) for tuning surface properties. This makes them highly promising for applications in microfluidics, microrobotics, smart textiles, self-cleaning, and anti-/de-icing. However, flexible cilia are fragile to mechanical damage, remaining a major obstacle to the application and industrialization of smart cilia arrays.

To overcome this bottleneck, the research group of Assoc. Prof. Jiang Youhua from the Mechanical Engineering (ME) Department of Guangdong Technion – Israel Institute of Technology (GTIIT) previously proposed "Armored Regenerable Cilia" in the top-tier nanoscience journal ACS Nano (Impact Factor: 16.1). Recently, the team has made further breakthroughs, publishing their research titled "Robust Smart Superhydrophobic Cilia" in the authoritative comprehensive journal Advanced Science (Impact Factor: 14.1). The first author of the paper is a doctoral student Wei Chuanqi; the second author is a master's student Li Baixue; the third author is Zhang Yimeng, an undergraduate student from the ME Program, Cohort 2022; the fourth author is the co-advisor Prof. Oleg Gendelman from Technion – Israel Institute of Technology, and Assoc. Prof. Jiang Youhua is the corresponding author.

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This work innovatively proposes a design for robust smart cilia: The surface features a "grid-like" metal mesh with each cell less than 3 millimeters in size, and hair-like cilia are horizontally planted on the sidewalls of the metal mesh. When the surface is under abrasion, the grinding head is too large to enter the cell, thus cannot contact the cilia on the grid sidewalls (Figure 1). When it is necessary to use cilia to control surface properties, a magnetic field is applied to the cilia, and the horizontal cilia re-align vertically with most of their parts exceeding the grid, thereby controlling the droplet behavior on the surface (Figure 2). This study concealed the vulnerability of flexible cilia and was the first to design and manufacture wear-resistant smart flexible surfaces, expanding their application scope.

Figure 1. Design of mechanically robust smart cilia

Figure 2. Abrasion test of robust smart cilia and their preserved functionalities

"Learning in Prof. Jiang's group gave me a more concrete understanding of the rigor and long-term commitment inherent in scientific research," shared the third author of the article Yimeng Zhang, a ME student from Cohort 2022 who joined the group in her junior year. Her research experience made her realize that research is not like "solving textbook problems", but rather a process of ongoing trial and error that gradually approximates the truth.

Group photo of some authors of the article: doctoral student Wei Chuanqi (left 1), Prof. Jiang Youhua (left 2), 

undergraduate student Zhang Yimeng (left 3), master's student Li Baixue (right 1)

Advanced Science

Advanced Science, part of the prestigious Wiley Advanced portfolio, is an open access interdisciplinary science journal publishing the best-in-class fundamental and applied research in materials science, physics, chemistry, medical and life sciences, and engineering, with the mission of giving top science the maximum accessibility through open access publishing.

Profile

Dr. Jiang Youhua received both his M.S. and Ph.D. from the Stevens Institute of Technology in 2014 and 2018, respectively. He then conducted two years' postdoctoral training at Northwestern University before joining the Mechanical Engineering department of GTIIT as an Associate Professor in October 2020.

Dr. Jiang Youhua specializes in Interfacial Phenomena with an emphasis on Soft and Smart Interfacial Phenomena, which involves droplet dynamics/statics on microtextured surfaces. His works (more than 40 papers) were mostly published in leading journals in Interfacial Phenomena and those as the first or corresponding authors appeared at Physical Review Letters, ACS Nano, Journal of Physical Chemistry Letters, Physical Review Fluids, Langmuir, Soft Matter, Journal of Colloid and Interface Science, Applied Physics Letters, ACS Applied Materials & Interfaces, etc. He received multiple grants in National Natural Science Foundation of China (NSFC) and Guangdong province. He also served as the reviewer for NSFC.

Jiang Youhua

Text/Photos: Dr. Jiang Youhua's Team, GTIIT News & Public Affairs