Currently, the main manufacturing processes for metamaterials include printed circuit boards(PCB)Photolithography, electron beam etching, etc. However, these processes3DThere are common problems in the manufacturing of metamaterial structures, such as cumbersome steps, high costs, and long processing times, which make it difficult to conform to curved surfaces and meet practical application conditions.3DThe manufacturing of surface conformal integrated metamaterials remains a major challenge.

Recently, Professor Sun Daoheng's research group from the School of Aeronautics and Astronautics at Xiamen University used surface projection micro stereolithography (P µ SL) 3D printing technology (microArch S240, Mofang Precision) combined with liquid metal filling method to prepare 3D orthogonal open resonant rings and curved conformal metamaterial structures. The embedded structural features can effectively protect the metal resonant layer from external environmental influences and have the advantages of macro micro and structure function integrated molding.

image1 3DPrinting embedded metamaterial preparation process

image2 Orthogonal Open Resonant Ring Metamaterial Structure and Dimensions:(a)Flat type;(b)Hemispherical compound eye metamaterial(The unit size is1.25mm)

The process flow is shown in Figure 1. Firstly, a 3D printer with an accuracy of 10 μ m (microArch S240, Mofang Precision) is used to prepare a model with a cavity of metamaterial microstructure. Then, the metamaterial metal microstructure is prepared using liquid metal vacuum filling method. The dimensions of the metamaterial structure are shown in Figure 2. The cross-sectional size of the open resonant ring is 0.1mm × 0.2mm, the top opening size is 0.3mm, and the outer diameter of the resonant ring is 1mm.

image3 Liquid metal filling and metamaterial performance testing:(a-b)Flat and biomimetic compound eye surface conformal metamaterials before and after liquid metal filling;(c-d)Metamaterial transmission performance testing

image3(a)for3Dprinted3DOrthogonal open resonant ring, conformal metamaterial mimicking compound eye surface, and local magnified image, as shown in the figure3(b)The metamaterial structure and its local amplification after filling with liquid metal. After filling the cavity of the metamaterial structure with liquid metal, a photosensitive resin is coated at the inlet of the liquid metal filling and cured by UV irradiation to seal the inlet. image3(c-d)Test results for planar and curved conformal metamaterials.

The study will3DThe combination of the flexibility of printing and the ease of flow and filling of liquid metals has opened up a new method for manufacturing complex metamaterial structures, no longer limited to complex structures. Laying the technological foundation for the structural innovation, functional innovation, and application innovation of metamaterials, and expanding the application scope of conformal metamaterials, such as3Doptics/Electromagnetic invisibility cloak, intelligent skin, super lens, etc.

The achievement is titled“3D Printed Embedded Metamaterials”Published in an international journal《Small》(IF = 13.281)The corresponding authors of the paper are Professor Sun Daoheng and Assistant Professor Chen Qinnan from the School of Aeronautics and Astronautics, Xiamen University. The first author is Zhang Kunpeng, a doctoral student from the School of Aeronautics and Astronautics, Xiamen University. This study was funded by the National Natural Science Foundation of China(51975498TheU1505243TheU2005214)The Shenzhen Science and Technology Innovation Committee's Technology Research and Development General Project(JSGG20201102165202007)Support and funding.

Original link:

https://doi.org/10.1002/smll.202103262