Author ORCID Identifier
Biosketch
Ms. Abirami Karthikeyan (born in 1994) received her B.E. degree in Electronics and Communication Engineering (ECE) from Anna University in 2015 and M.E. degree in Communication Systems with distinction in 2017.
In 2022, she joined the School of Electrical and Electronics Engineering, SASTRA Deemed University, as a Junior Research Fellow (JRF) under the UGC, and was later promoted to SRF. She carried out her doctoral research in the domain of RF and microwave systems, with emphasis on microwave sensor design for Industrial Internet of Things applications. Her research contributions include innovative sensing methodologies for food safety and non-invasive industrial monitoring.
Date of Award
7-7-2025
Document Type
Thesis
School
School of Electrical & Electroncis Engineering
Programme
Ph.D.-Doctoral of Philosophy
First Advisor
Dr. A. Rajesh
Keywords
Internet of Things, Non-Invasive Sensors, Milk Adulteration, Grain Microwave, Formalin Detection
Abstract
The industrial sector has been revolutionized by Industrial Revolution 4.0 with the advent of the Internet of Things (IoT) which integrates the physical environment using smart sensors and Artificial Intelligence (AI) mechanisms. This demands the design of smart sensors and actuators to improve the quality of services in Industrial IoT (IIoT). The sensor design using the microwave resonating principle has attracted the research and industrial community for portable, non-invasive, non-destructive and hygienic means to evaluate the quality of substances in the food and farming industry. The microwave planar sensor has advantages in terms of low footprint, low cost, and ease of integration with the existing framework. Alternatively, the microwave sensors have design Challenges in terms of sensitivity and selectivity based on the choice of resonators, substrates and frequency of operation used for a particular application.
The research aims to develop non-invasive near-field microwave sensors for industrial Internet of Things applications with the IEEE 154 standard, focusing on enhanced sensing with real-time quality assurance in dairy, agricultural warehouses, and aquaculture industries. This study focuses on the various techniques and on the principle of operation in the design for microwave sensing, namely, Split Ring Resonator (SRR), metamaterial planar sensor, Complementary SRR (CSRR) sensor, Substrate Integrated Waveguide (SIW) sensor and microstrip ring resonators will be investigated for various substrates, materials under test and frequencies of operation. This work includes studying numerical methods for complex permittivity extraction and measurement techniques.Further, the study focuses on the quality factor analysis, sensitivity analysis, detectivity range, and possible location of a device under test.
The proposed sensors include a milk adulteration identification sensor, a grain moisture and gas detection sensor, and a formalin contamination detection sensor in fish. This noninvasive milk adulteration sensors, double heterogeneous ring resonating sensor and assimilated ring resonating sensor identifies adulteration substances like urea, water, detergent and starch, safeguarding the purity and safety of dairy products. The grain microwave sensors, namely, snowflake resonating sensor measures the moisture content and ammonia gas in stored grains to avoid spoilage. Snowflake resonating sensor with metasurface enables non-invasive detection of grain during storage and processing. Further, substrate integrated waveguide enabled identical circular patch sensor and triple oval planar resonating sensor identifies the presence of formalin content in fish, a toxic preservative often used to prolong freshness. These sensors displays a promising role in food safety, quality control, and public health.
Recommended Citation
K, Abirami Ms, "Non-Invasive Near-Field Microwave Sensors for Industrial Internet of Things Applications" (2025). Theses and Dissertations. 1.
https://knowledgeconnect.sastra.edu/theses/1
Graphical Abstract