Recently, the research team led by Sheng Yan from the Institute of Advanced Studies at Shenzhen University published their review article entitled “Gallium-Based Liquid Metals: Optical properties, Applications, and Challenges” in Advanced Optical Materials. Xiuru Wu, a master’s student at the Nanophotonics Research Center of Shenzhen University, is the first author of the paper, with Professor Hui Fang and Sheng Yan as corresponding authors. The Institute of Advanced Studies at Shenzhen University is the first affiliation. The work also received support from Professor Xing Ma at Harbin Institute of Technology, Shenzhen campus. This achievement was supported by the National Natural Science Foundation, the Guangdong Provincial Basic and Applied Basic Research Fund, and the Shenzhen Science and Technology Innovation Committee.

Originating from the intrinsic metallic and liquid natures, gallium-based liquid metals (Ga-based LMs) have been greatly developed in the research of soft electronics, chemical synthesis, and other fields due to their fascinating characteristics. Meanwhile, the development and application of metal optics can help modern medicine and industry reach rapid developmental stages, such as disease imaging, photothermal treatment, and sensor detection. Ga-based LMs can achieve wideband-tunable plasmonic resonance and exhibit characteristic optical responses owing to their unique polymorphisms, undercooling, and superior mobility. However, a notable limitation is the scarcity of comprehensive summaries on this topic. Although existing reviews have summarized the applications of Ga-based LMs from a photonic perspective, there is a noticeable gap in the systematic introduction of the optical properties of Ga-based LMs and their underlying principles. Ga-based LMs offer promising possibilities for optical applications，such as optical switches and memory, optical sensor, and so on.

According to the possibilities of Ga-based LMs in optical applications,Yan’s team from the Institute for Advanced Study of Shenzhen University reviewed the research of Ga-based LMs optics and discussed its future prospects.In this review，we emphasize reviewing the optical properties and applications of LMs. Starting with the introduction of pure Ga, the dielectric function of Ga in different states was summarized according to the polymorphism. Using the EGaIn LM alloy as an example, the dielectric function of Ga-based LMs is summarized. We also review their plasmonic properties based on existing reports and introduce applications that correspond to their optical properties (Figure 1). Finally, we provide a perspective on the opportunities and challenges of Ga-based LMs in future optical applications.

Figure1Outline of Ga-based LMs for optical applications.

Link to the original article of the paper：https://onlinelibrary.wiley.com/doi/10.1002/adom.202301180