Ultrarobust, Highly Sensitive and Swinging‐Independent Droplets‐Spatial Manipulator Enabled via Laser‐Printed Magnetically Actuated Shape‐Morphing Microshutters

Abstract

Spatial manipulation of liquid droplets holds great significance in various areas from laboratory research to everyday life. Unfortunately, current manipulators are limited to lower responsivity and unreliable durability together with swinging‐dependent manner. Herein, an ultrarobust, sensitive, and swinging‐independent droplet‐spatial manipulator is reported, namely, magnetically actuated shape‐morphing microshutters (MASM) enabled by laser printing and soft transfer technique. Leveraging the loading/discharging of a remote magnet, the MASM can be reversibly switched between a bending mode and an erect mode within 1 s, thereby modulating the three‐phase contact line (TCL). The underlying hydrodynamics is that B‐mode MASM renders a longer TCL and an exaggerated adhesion force (Fa), thereby pinning the surface droplets under the assistance of a magnetic field. Once the magnetic trigger is removed, the bent shutters reverse back to the E‐mode so as to grant a shorter TCL and smaller Fa. Based on this phenomenon, the droplet's capture/release can be readily realized in response to magnetic stimuli. Last but not least, by taking advantage of an optimized MASM, pattern‐free configuration and droplets on‐demand marriage and targeted chemical reaction together with programmable circuit remedy are deployed. This work provides impetus for researchers in constructing intelligent droplet manipulation systems for multidisciplinary areas.

Keywords

• droplet-spatial manipulators
• femtosecond laser
• magnetism-responsive microshutters
• switchable adhesion