Fabrication of metal hollow microstructures via dynamically modulated meniscus-confined electrodeposition

Metal hollow microstructures (MHMs) demonstrate exceptional application potential in chemical catalysis and energy storage systems due to their distinctive architectural advantages, including high surface-to-volume ratio, reduced mass density, and superior mechanical robustness. However, developing flexible, cost-effective, and reliable fabrication techniques remains a critical challenge. To address this limitation, we developed an innovative meniscus-confined electrodeposition (MCED) control strategy based on the fusion of square-wave and AC dynamic voltage modulation. The control strategy comprises four progressive phases: (i) cyclic voltammetric analysis for determining optimal deposition voltage window (0.5∼1.2 V) and pulse duty cycle parameters (30∼70%); (ii) Herein, we employ a multiphysics simulation approach to investigate the dynamic changes in ion transport and the evolution of the deposition front during the electrodeposition process. The simulation results indicate that, compared to the square-wave modulation mode, the deposition rate is increased by 2 times under the AC dynamic voltage modulation mode; (iii) Duty cycle optimisation achieves annular deposition patterns with controlled geometric features (width: 3.2±0.3 μm, thickness: 0.41±0.05 μm); (iv) Using a sinusoidal pulse modulation strategy, vertically arranged MHMs with adjustable dimensions (height 45 ± 2 μm, wall thickness 3.1 ± 0.2 μm, deposition rate 0.32 μm/s) can be precisely manufactured.