Curvature-induced liquid manipulation by customizable morphing surfaces

Liquid manipulation on surfaces plays an important role in engineering and biomedical applications such as water harvesting, microfluidics, and disease diagnostics. Bioinspired structured surfaces and movable surfaces driven by external fields have been proposed to regulate liquid spreading. Yet, it remains challenging to design a liquid operation surface with the flexibility of liquid operation while maintaining operation stability and system simplicity. To resolve these challenges, here we introduce a new design paradigm for developing surfaces formed by sophisticated arrays of magnetically responsive micropillars. The intrinsic shape and curvature of the micropillars can induce an unbalanced Laplace pressure to drive the directional transport of liquids with different surface tensions and viscosities. In contrast to traditionally engineered surfaces that rely on programmed magnetic fields to propel liquids, this novel magnetized surface relies solely on static magnetic fields to modify its configurations for liquid transport, enabling on-demand liquid transport with controllable speeds and directions as well as multi-liquid operations. This investigation offers new insights into the development of functional liquid operation surfaces. It also opens a new avenue for real-world applications in portable chemical reaction platforms and automated analysis devices.