Artificial Sharkskin: Fabrication of Staggered Overlapped Microdenticles

In liquid crystalline elastomers, anisotropy in molecular alignment governs direction of mechanical actuation upon exposure to external stimuli.¹ Similarly, the arrangement direction of magnetic particles determines magnetomechanical actuation of polymer composites. In micropillar arrays, chain-like arrangement of magnetic particles can induce bending or twisting actuation of micropillars under linear external magnetic field.² When magnetic particles are arranged along the principal axis of the micropillar, the perpendicular external magnetic field produces bending actuation. In the same magnetic field condition, twisting actuation is induced with magnetic particles arranged along the short-axis of micropillars.² The strain responsivity of magnetic actuation can be enhanced by employing anisotropic micropillar geometry for anisotropic stress distribution.³ Based on the manetic bending actuation of anisotropic microdenticles, staggered-overlapped three-dimensional microarchitectures are constructed to mimick artificial sharkskin, a feat difficult to achieve by conventional microfabrication techniques.⁴ In this presentation, various anisotropic functionalities of this artificial sharkskin will be discussed.


Acknowledgment
This work was supported by Air Force Office of Scientific Research/Asian Office of Aerospace Research and Development (AFOSR/AOARD) (FA2386-22-1-4086), National Research Foundation of Korea (NRF-2022R1A2C2002911).

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