Magnetically-Driven Reconfigurable Cilium Array with Tunable Wettability for Dynamic Display and Controllable Microreactio

Article Magnetically-Driven Reconfigurable Cilium Array with Tunable Wettability for Dynamic Display and Controllable Microreactio Zijing Quan 1, Yuhan Zhang 1,*, You Pan 1, Zhongyi Yang 1, You Chen 1, Fawei Rui 1, Letian Li 1, Bo Li 1,2,*, Shichao Niu 1,2,3,*, Zhiwu Han 1,2,3, and Luquan Ren 1,2,3 1 Key Laboratory of Bionic Engineering (Ministry of Education), Jilin University, Changchun 130022, China 2 National Key Laboratory of Automotive Chassis Integration and Bionics, Jilin University, Changchun 130022, China 3 Institute of Structured and Architected Materials, Liaoning Academy of Materials, Shenyang 110167, China * Correspondence: [email protected] (Y.Z.); [email protected] (B.L.); [email protected] (S.N.) Received: 3 March 2025; Revised: 17 March 2025; Accepted: 25 March 2025; Published: 28 March 2025 Abstract: Efficient droplet transport plays an important role in many fields such as liquid collection, microfluidic management, and reaction control. However, it remains a key challenge to achieve fast and precise droplet motion control along a predetermined path. Herein, a magnetically driven cilium array (MDCA) was developed by a simple one-step spraying method. The MDCA exhibits both upright and prostrated states under a programmable magnetic field, achieving in-situ pinning and driving of the droplets, respectively. In particular, the MDCA modified by the silicone oil can not only be used for precise droplet manipulation on the spatio-temporal scale (S-shaped trajectory transport, selective control of target droplets, and velocity control) but also provides a self-enclosed space for droplet fusion for chemical microreactions, allowing fine-tuning of reaction parameters and isolation from external contamination. Based on the theoretical analysis of droplet transport, MDCA can be applied to the development of dynamic digital displays and chemical microreactors and provides inspiration for the development of environmental monitoring, drug delivery, and energy purification.