CN211741070U

CN211741070U - Refractive index sensing chip based on metal metamaterial

Info

Publication number: CN211741070U
Application number: CN201922166973.3U
Authority: CN
Inventors: 陈华腾; 郎婷婷; 王钢棋
Original assignee: China Jiliang University
Current assignee: China Jiliang University
Priority date: 2019-12-06
Filing date: 2019-12-06
Publication date: 2020-10-23
Anticipated expiration: 2029-12-06

Abstract

The utility model relates to a refractive index sensing chip based on metal metamaterial; the sensing chip consists of a metal metamaterial layer (1) and a quartz substrate layer (2); the metal metamaterial layer (1) is formed by a periodic array with a unit structure of a symmetrical regular triangle; the unit structures are in a periodic sequence in both the x direction and the y direction and are positioned on the substrate layer (2); when terahertz waves are normally incident to the sensing chip, galvanic couple resonance is generated, and a transmission peak appears at the frequency of 1.50 THz; the refractive index sensitivity of the structure was calculated to be 57 GHz/RIU. The refractive index sensing chip based on the metal metamaterial has the advantages of simple structure, low cost, benefit to mass production and the like, and has a good application prospect in the aspect of biological detection.

Description

Refractive index sensing chip based on metal metamaterial

Technical Field

The utility model relates to a sensor chip research of refracting index based on metal metamaterial

Background

THz is widely applied in the fields of communication, medicine, safety and the like; furthermore, the low average power and non-ionicity of THz waves make them a preferred choice for detection in the biomedical and chemical fields. There is currently a portable THz spectroscopy tool that facilitates on-site detection and identification of high signal-to-noise ratios, but is limited by the thickness and shape of the item being detected. The metamaterial is an artificially arranged sub-wavelength structure, and the biological sensing chip combined with the metamaterial with typical resonance provides a good platform for the ultrahigh sensitivity of the THz device, and allows the detection of a very small amount of molecules or biological cells. More importantly, the metamaterial-based biosensor chip is low in cost and does not need a traditional fluorescent labeling program. The advantages of the biological sensing chip based on the metamaterial provide a label-free, low-cost and rapid detection way for cell detection; is an effective method for future biosensing and disease detection.

Disclosure of Invention

The utility model relates to a detect sensing chip research of object refracting index for improve the sensitivity of refracting index sensing chip, increase the accuracy that detects.

In order to achieve the purpose, the experiment provides the following scheme: the sensing chip consists of a metal metamaterial layer (1) and a quartz substrate layer (2); the metal metamaterial layer (1) is formed by a periodic array with a unit structure of a symmetrical regular triangle; the unit structures are in a periodic sequence in both the x direction and the y direction and are positioned on the substrate layer (2); when terahertz waves are normally incident to the sensing chip, galvanic couple resonance is generated, and a transmission peak appears at the frequency of 1.50 THz; the refractive index sensitivity of the structure was calculated to be 57 GHz/RIU. The refractive index sensing chip based on the metal metamaterial has the advantages of simple structure, low cost, benefit to mass production and the like, and has a good application prospect in the aspect of biological detection. And finishing the manufacture of the whole sensing chip structure by utilizing a wet etching technology.

The metal metamaterial layer (1) has the conductivity of 4.56 multiplied by 10⁷S/m metal gold, wherein the period of the metal metamaterial unit structure in the x and y directions is P_x＝120μm，P_y60um, the thickness in the z direction is 0.1 μm, the side length of the symmetrical regular triangle unit structure (3) is 50 μm, and the gap is 20 μm; the base layer (2) is quartz having a dielectric constant of 4.41, and has a height h of 30 [ mu ] m in the z direction;

the utility model has the advantages that:

the utility model discloses based on gold metamaterial layer unit structure array periodic arrangement, terahertz wave incides on the biosensing chip, coupled on advancing the sensing chip and arouse electromagnetic resonance, form the transmission peak, realize the measurement to biological cell volume through resonant frequency's displacement, sensing chip simple structure, the material is ordinary, and easily processing has higher sensitivity in the performance, forms the resonance spectrum peak at 1.50THz, and its sensitivity can reach 57GHz RIU.

Drawings

The present invention will be further described with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a schematic view of the periodic structure of the symmetrical regular triangle unit of the present invention;

FIG. 2 is a periodic top view of the symmetrical regular triangle unit structure of the present invention;

fig. 3 is a simulated electric field diagram of the symmetrical regular triangle unit structure of the present invention;

FIG. 4 is the magnetic field simulation diagram of the symmetrical regular triangle unit structure of the present invention

FIG. 5 is a transmission spectrum of the structure of the present invention under different refractive indexes;

fig. 6 is a fitting graph of the resonant frequency of the structure of the present invention at different refractive indices.

Detailed Description

The invention will be further explained and explained with reference to the drawings and the specific examples.

The utility model provides a symmetrical regular triangle terahertz biological sensing chip based on a gold metal metamaterial, which comprises a metal metamaterial layer (1) and a quartz basal layer (2); the metal metamaterial layer (1) is formed by a periodic array with a unit structure of a symmetrical regular triangle; the unit structures are in a periodic sequence in both the x direction and the y direction and are positioned on the substrate layer (2); as shown in the attached figure 1, for the unit structure schematic diagram of the present invention in a period, the period of the metal metamaterial unit structure in two directions of x and y is P_x＝120μm，P_y60um, the thickness in the z direction is 0.1 μm, the side length of the symmetrical regular triangle unit structure (3) is 50 μm, and the gap is 20 μm; the base layer (2) is quartz having a dielectric constant of 4.41, and has a height h of 30 [ mu ] m in the z direction; a periodic top view of a symmetrical regular triangular cell structure is shown in fig. 2.

Fig. 3 and fig. 4 are the simulation electric field diagram and the magnetic field diagram of the symmetrical regular triangle unit structure of the present invention, respectively, and can be seen from the simulation result: the incidence of terahertz waves on the structure will generate galvanic resonance. Fig. 5 shows the transmittance of the CST electromagnetic simulation software of the present invention at the working wavelength band, which can be seen from the simulation result: a transmission peak at 1.50 THz; the peak of the transmission peak shifts when the refractive index changes. Fig. 6 is the resonant frequency fitting graph of the structure of the present invention under different refractive indexes, viewed from the simulation result: a linear relation exists between the refractive index and the resonant frequency; f (resonance frequency) — 57 × N (refractive index) + 1562; and the sensitivity through the book refractive index reaches 57GHz/RIU, consequently the utility model discloses have the advantage that sensitivity is high on the performance. Moreover, the utility model adopts gold metal and silicon material, which has low cost and easy processing.

Claims

1. A refractive index sensing chip based on metal metamaterial is characterized in that: the sensing chip consists of a metal metamaterial layer (1) and a quartz substrate layer (2); the metal metamaterial layer (1) is formed by a periodic array with a unit structure of a symmetrical regular triangle unit structure; the unit structures are in a periodic sequence in both x and y directions and are positioned on the quartz substrate layer (2).

2. The refractive index sensing chip based on the metal metamaterial according to claim 1, wherein: the metal metamaterial layer (1) has the conductivity of 4.56 multiplied by 10⁷S/m metal gold, wherein the period of the metal metamaterial unit structure in the x and y directions is P_x＝120μm，P_y60um, a thickness t of 0.1 um in the z direction, a side length f of 50 um, and a gap d of 20 um of the symmetrical regular triangle unit structure (3)m; the base layer (2) is quartz having a dielectric constant of 4.41, and has a height h of 30 [ mu ] m in the z direction.