Z-slotted Silicon Dioxide Based Tunable Polarization Converter Design Using Graphene-VO2 Composite for Detection of Cancer

IF 2.8 3区材料科学 Q3 CHEMISTRY, PHYSICAL

Silicon Pub Date : 2024-11-21 DOI:10.1007/s12633-024-03198-z

Priyanka Das, Keertana Sarvani Chilakapati

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引用次数: 0

Abstract

The terahertz (THz) band can be deployed for label-free detection of malignant cells by using a cross-polarization converter sensor based on metasurfaces. Here, a metamaterial-based polarization converter is designed which can be tuned by varying the chemical potential of graphene. Dual band circular polarized (CP) waves are generated by an asymmetric Z-slotted graphene patch on a silicon dioxide constituted substrate. A Z-shaped conductor made of vanadium dioxide (VO₂) is added in the slot to convert the metasurface from a CP converter into a cross-polarization converter. Optimizations in the design have been performed using Actor-Critic method with A3C (Asynchronous Actor-Critic Agents), which is a type of reinforcement learning algorithm. The apparatus is engineered to function based on the idea of refractive index (RI) sensing, which involves detecting the frequency shift of the maximum polarization conversion peak in the presence of the target compound. Insulator to metallic phase conversion of VO₂ alters its dielectric properties like permittivity and conductivity due to variation of the anatomy of electron orbitals. By increasing the temperature of VO₂, tunability in polarization conversion can be achieved due to its phase transition. Two degrees of freedom are thus present for tunability in polarization conversion. The change in maximum polarization conversion frequency is proportional to the RI difference between malignant and healthy cells. Peak sensitivity of the proposed metasurface is 420 GHz/RIU with maximum polarization conversion efficiency 98.3%. Finite integration based numerical simulations have been used to investigate the operating principle of the proposed polarization converter.

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来源期刊

Silicon CHEMISTRY, PHYSICAL-MATERIALS SCIENCE, MULTIDISCIPLINARY

CiteScore

5.90

自引率

20.60%

发文量

685

审稿时长

>12 weeks

期刊介绍： The journal Silicon is intended to serve all those involved in studying the role of silicon as an enabling element in materials science. There are no restrictions on disciplinary boundaries provided the focus is on silicon-based materials or adds significantly to the understanding of such materials. Accordingly, such contributions are welcome in the areas of inorganic and organic chemistry, physics, biology, engineering, nanoscience, environmental science, electronics and optoelectronics, and modeling and theory. Relevant silicon-based materials include, but are not limited to, semiconductors, polymers, composites, ceramics, glasses, coatings, resins, composites, small molecules, and thin films.