3D printing-assisted and magnetically-actuated superhydrophobic surfaces for droplet control

Recent Advances in Superhydrophobic Materials Development for Maritime Applications

“…More recently, Park et al conducted an innovative study that combined biomimetic principles, magnetic responsive materials, and 3D printing to develop a magnetically controllable micro-patterned wall arrays (MCMAs) film (Figure 5d). [94] They employed a simple and cost-effective fused filament fabrication (FFF)-type 3D printing method, which allowed for the rapid and convenient creation of numerous nano-micron scale cilia structures on the substrate surface. Interestingly, the filament laminating process during FFF-type 3D printing resulted in a characteristic "staircase effect", [95] which produced a sharp microstructure when the printed structure was cast on PDMS containing magnetic particles.…”

Magnetically responsive manipulation of droplets and bubbles

“…The microplate structures have wide side surfaces, and they can show sequential abrupt inversion, cluster bending, or unidirectional bending under the control of the magnetic field. [49][50][51][52][53][54][55][56][57] As shown in Figure 3a, the droplet can be transported in the horizontal direction by the sequential abrupt inversion of the microplates induced by the periodic magnetic field. By controlling the bending and uprighting of the microplates, the adhesion state between the droplet and the structure can be adjusted, enabling the capture and release of the droplet in the vertical direction.…”

“…49 In addition, the magnetically responsive microplate array can also manipulate the droplet by inducing surface tension imbalance of the droplet through unidirectional bending or directly pushing the droplet through cluster bending and real-time reconstruction. 51,55,56 Motile cilia widely exist in many organs and play a crucial role in the transport of substances like sputum and ova. [61][62][63] Similar to motile cilia, magnetically responsive microcolumn or microcilia can produce F I G U R E 3 Magnetically responsive surface-based droplet manipulation.…”

“…The common magnetically responsive structures include microplate, microcolumn (regularly distributed elongated structures), microcilia (randomly distributed elongated structures), and microdimple. The microplate structures have wide side surfaces, and they can show sequential abrupt inversion, cluster bending, or unidirectional bending under the control of the magnetic field 49–57 . As shown in Figure 3a, the droplet can be transported in the horizontal direction by the sequential abrupt inversion of the microplates induced by the periodic magnetic field.…”

“…By controlling the bending and uprighting of the microplates, the adhesion state between the droplet and the structure can be adjusted, enabling the capture and release of the droplet in the vertical direction 49 . In addition, the magnetically responsive microplate array can also manipulate the droplet by inducing surface tension imbalance of the droplet through unidirectional bending or directly pushing the droplet through cluster bending and real‐time reconstruction 51,55,56 …”