In 1965, before cofounding Intel, Gordon Moore astutely observed that the number of transistors in dense integrated circuits doubles about every two years. Today, a new trend – “More than Moore” – is being driven by functionality-enhancing innovations with 2D materials that, among other advantages, may significantly accelerate microchip development.
In contrast to traditional bulk materials like silicon and germanium, 2D materials such as graphene exhibit extraordinary electrical, optical, and mechanical properties due to their layered structures. As emerging nanomembranes, graphene-like, layered 2D materials are being constructed into 3D tubular structures, producing unparalleled advantages for a range of applications and potential for microchip integration.
Wu et al. reviewed state-of-the-art methods for development and applicability of these promising nanomembrane structures.
“Some are based on characteristics of the 2D materials; others are more general and have existed for a long time,” said coauthor Yongfeng Mei. “The ‘rolled-up method’ with auxiliary layers, for example, derives from the self-assembly of traditional nanomembrane materials. Depositing a stress layer with controllable parameters on 2D materials enables manufacture of a tubular device with a controllable diameter and number of turns with assistance of the micro-nano process, which has yield and quality advantages and is compatible with the chip process.”
Notably, as the paper explains, tubular 2D materials retain their original desirable properties after new attributes, such as altered energy band structures, increased stability in atmospheric settings, and lubricated inner and outer surfaces, are incorporated.
“These benefits may be fully utilized … in electronics, photodetectors, optical microcavities and microrobots,” said Mei.
The team also presented challenges to application of these materials, including wafer-scale 2D material transfer, device assembly yield, and system-level application verification.
Source: “Progress and challenges on 3D tubular structures and devices of 2D materials,” by Binmin Wu, Ziyu Zhang, Chao Wang, Enming Song, Jizhai Cui, Gaoshan Huang, Peng Zhou, Zengfeng Di, and Yongfeng Mei, Applied Physics Letters (2022). The article can be accessed at http://doi.org/10.1063/5.0098838.
