Coatings for Core–Shell Composite Micro‐Lattice Structures: Varying Sputtering Parameters

Magnetron sputtering has garnered increased attention as a versatile deposition method for generating novel core–shell composite nano‐ and micro‐lattice materials spanning a wide range of properties and functionalities. Sputtering offers an expansive material workspace consisting of a wide range of ceramics, single‐element metals, and alloy systems. However, achieving uniform coatings on such fine‐featured structures remains a challenge. Thus, herein, a foundational assessment of various sputtering configurations, cathode geometries, and deposition parameters is carried out to investigate their implications on the coating thickness and uniformity of 3D micro‐lattice scaffolds. Specifically, tetrahedral‐truss structures fabricated via direct laser writing are coated by leveraging planar and inverted cylindrical magnetron cathodes at select deposition rates, sputtering powers, and Ar working pressures. Both plasma focused ion beam and microtome sectioning techniques are employed to evaluate the cross section of individual struts and assess overall uniformity. Overall, the influence of key sputtering factors on the design and development of core–shell composite nano‐ and micro‐lattice materials is highlighted and a pathway for future sputter coating optimization on these complex structures is provided.