Control of Droplet Impact through Magnetic Actuation of Surface Microstructures

Published: 28 February 2023| Version 1 | DOI: 10.17632/s34pwpv4dr.1
Contributors:
,
,
,
,
,
,

Description

An effective method for on-demand control over the impact dynamics of droplets on a magnetoresponsive surface is reported. The surface is comprised of micrometer-sized lamellas from a magnetoactive elastomer on a copper substrate. The surface itself is fabricated using laser micromachining. The orientation of the lamellae is switched from edge-on (orthogonal to the surface) to face-on (parallel to the surface) by changing the direction of a moderate (< 250 mT) magnetic field. This simple actuation technique can significantly change the critical velocities of droplet rebound, deposition, and splashing. Rebound and deposition regimes can be switched up to Weber number We < 13±3, while deposition and splashing can be switched in the range of 32 < We < 52. Because a permanent magnet is used, no permanent power supply is required for maintaining the particular regime of droplet impact. The presented technology is highly flexible and enables selective fabrication and actuation of microstructures on complex devices. It has great potential for applications in soft robotics, microfluidics, and advanced thermal management. The following video files show typical water droplet impacts on different surfaces: • Droplet deposition on flat MAE at We = 10 (flat_We10.avi) • Droplet deposition on flat MAE at We = 44 (flat_We44.avi) • Droplet circular splash on flat MAE at We = 100 (flat_We100.avi) • Droplet deposition on “face on” MAE at We = 10 (side view: face_on_We10(side).avi, front view: face_on_We10(front).avi) • Droplet deposition on “face on” MAE at We = 44 (side view: face_on_We44(side).avi, front view: face_on_We44(front).avi) • Droplet parallel splash on “face on” MAE at We = 76 (side view: face_on_We76(side).avi, front view: face_on_We76(front).avi) • Droplet circular splash on “face on” MAE at We = 100 (side view: face_on_We100(side).avi, front view: face_on_We100(front).avi) • Droplet rebound on “edge on” MAE at We = 10 (side view: edge_on_We10(side).avi, front view: edge_on_We10(front).avi) • Droplet penetration on “edge on” MAE at We = 17 (side view: edge_on_We17(side).avi, front view: edge_on_We17(front).avi) • Droplet parallel splash on “edge on” MAE at We = 44 (side view: edge_on_We44(side).avi, front view: edge_on_We44(front).avi) • Droplet circular splash on “edge on” MAE at We = 172 (side view: edge_on_We172(side).avi, front view: edge_on_We172(front).avi)

Files

Categories

Elastomeric-Based Composite, Droplet, Laser Ablation, Microstructure Characterization, Impact Dynamics

Funding

Javna Agencija za Raziskovalno Dejavnost RS

P1-0192

Javna Agencija za Raziskovalno Dejavnost RS

P2-0392

Javna Agencija za Raziskovalno Dejavnost RS

J1-3006

German Research Foundation

437391117

Licence