Modeling and Analysis of SOI Gratings-Based Opto-Fluidic Biosensor for Lab-on-a-Chip Applications

Abstract

† This paper is an extended version of our paper published in: Venkatesha, M.; Vismaya, K.R.; Prashanth, A.U.; Vyshnavi, M.; Narayan, K. Modeling and Analysis of SOI Grating Coupler for Bio-sensing Applications.Abstract: The design, modeling, and analysis of a silicon-on-insulator (SOI) grating coupler integrated with a microfluidic channel for lab-on-a-chip applications are presented. The grating coupler was designed to operate at 1310 nm. The simulated SOI structure consisted of a 220 nm top-Si device layer with an integrated waveguide, grating coupler, and a buried oxide layer of 2 µm. A rectangular microfluidic channel was deposited on the SOI optical grating structure for light and fluid interaction. The fluidic flow through the device was driven by centrifugal and Coriolis forces. The grating structure was designed to achieve a maximum coupling efficiency at the optimized injection angle of the light source. The sensitivity of the grating structure could be analyzed and evaluated using the change in coupled power as a function of the effective refractive index and was found to be 0.928 × 10 −6 RIU. The SOI optical grating structure along with the micro fluidic channel on top could be effectively used as an absorbance-based lab-on-a-chip biosensor.Photonics 2019, 6, 71 2 of 9 changes in physical parameters such as temperature, pressure, and magnetic field [17][18][19][20][21]. The Bragg wavelength for optical sensing applications is given by Equation (1) [22]:

Reusable, Non-Invasive, and Ultrafast Radio Frequency Biosensor Based on Optimized Integrated Passive Device Fabrication Process for Quantitative Detection of Glucose Levels

“…A biosensor can convert different concentrations of glucose into corresponding electrical signals for output, which has advantages of high accuracy, fast analysis, low cost, good repeatability, simple operation and high specificity by comparing with traditional detection methods [10][11][12][13][14][15][16]. With the aid of chips, microfluidics systems and labs-on-a-chip, biosensor technology have developed rapidly and can be divided into electrochemical biosensors and optical biosensors based on the type of signal conversion [17][18][19][20][21][22][23][24][25][26]. Electrochemical biosensors enable the detection of biomarkers by adding specific enzymes on the electrodes, which has many advantages, such as high sensitivity, simple operation and cost-effective [27][28][29].…”