3D Printing of A Thermally Programmable Conformal Metasurface

Abstract

The curved surfaces conformality has become the coming barrier to the implementation of the metasurface carpet cloaks. A curved conformal strategy that can balance the electromagnetic performances and the manufacturing challenges of metasurface simultaneously is highly in demand, but yet underexplored. Herein, a novel thermal programming 3D‐printing method for curved conformal metasurface is proposed. Owing to the glass‐rubber transition characteristics of thermoplastic polymers, the advantages of rigid substrate and flexible substrate are fully utilized to achieve the conformality of metasurface, which ingeniously reduces the manufacturing complexity and ensures the electromagnetic performances. As a proof, an arched metasurface carpet cloak composed of the easy‐bending unit cells is designed and fabricated by the composite fused deposition molding of polylactic acid and Sn‐Bi materials with the thermal programming process. Experiments prove that the maximum reduced total radar cross section of the conformal cloak reaches about −9.4 dB while the 3 dB reduction bandwidth is ≈26.6%. The excellent cloaking performance of the metasurface sample demonstrates the effectiveness of this curved conformal method. This work provides a viable implementation strategy for complex curved metasurface and will substantially promote the applications of the conformal invisibility cloaks.

Dynamic bond exchangeable thermoset vitrimers in 3D‐printing

“…14,16,49,56 Generally, thermoplastic-based 3D-printed systems have evolved due to their ease of the processing and temperature independence. 61 In contrast, thermoset printed materials have prominent mechanical properties linked to their crosslinked states; however, the nonprocessable and specific curing conditions (i.e., except photopolymer certain temperatures are required for curing the conventional polymers) have restricted their presence in several fields. 62 To mitigate this constraint, Wang et al have investigated and emphasized the bio-based thermoset in 3D printing materials, which could have degraded effectively via the environmental conditions and provide a sustainable circular bioeconomy; though, the material F I G U R E 2 Utilization of functional polymers for different applications via 3D printing 54 [Color figure can be viewed at wileyonlinelibrary.com] properties (like geometrical stability) have not been comparable like a synthetic polymer utilized printed materials.…”

An Additively Manufactured Wide Angle and Broadband Electromagnetic Camouflage Metasurface

“…Meanwhile, we explore a composite fused deposition molding (FDM) packaging strategy for multilayer heterostructures, which provides a complete additive manufacturing method for metasurface consisting of metal meta‐atoms and dielectric substrates simultaneously. Combined with the thermal programming curved conformal method in our previous work, [ 37 ] the designed metasurface is successfully fabricated. Measurement results demonstrate that the metasurface sample achieves polarization‐insensitive cloaking and illusion functions in two preset frequency bands, and the effective incidence angle range reaches about −45° to 45°.…”

Additively Manufactured Polarization Insensitive Broadband Transmissive Metasurfaces for Arbitrary Polarization Conversion and Wavefront Shaping

“…[41] For example, conformal carpet cloaks are demonstrated using additive manufacturing [42] with a thermally programmable feature. [43] Different kinds of gradient-index metamaterial lenses from acoustic to terahertz regions were demonstrated using fused deposition modeling or micro-stereolithography. [44][45][46][47] Undoubtedly, the rise of additive manufacturing helps unlock the great potential of metamaterials, paving the way to the future high-efficient, multi-functional, and cost-effective intelligent systems.…”