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Novel Capacitive Sensors for Chemical and Physical Monitoring in Microfluidic Devices

Rajan, Parthiban
http://orcid.org/0000-0002-4864-7618
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1549449776383119

Abstract Details

2019, Doctor of Philosophy (PhD), Ohio University, Electrical Engineering & Computer Science (Engineering and Technology).
Lab-on-a-Chip (LoC) devices integrate the elements of advanced electronics and microfluidic technology to create robust, cost-effective, state-of-the-art chemical, environmental and biomedical analysis platforms to be used for wearable health monitors, analytical monitoring and portable point-of-care diagnostics solutions. Demand in these applications are expected to grow exponentially in next decade and efficient, low-cost capable microfluidics platforms can define the success of this on-going revolution along with the printed electronics (PE) that enhance the capability, affordability and scalability of LoC systems. Key to design of such compact and low-cost LoC systems is the variety, size and capabilities of novel nanosensors. Accordingly, this dissertation aims at fusing the PE and microfluidic technology in creating application-specific novel LOC devices. In particular, the vast prospects of capacitive sensing technology have been comprehensively explored. By altering the printed capacitive design elements, microfluidic design and flow properties, a number of novel nanosensors categorized into capacitance based physical and chemical capacitive sensors have been developed. In this dissertation, the concept of capacitive sensing, with a distinct focus on planar printed interdigitated capacitors (IDC) integrated into microfluidic devices, has been investigated. Initial focus has been on process development for efficient activation of printing surfaces for IDC fabrication and microfluidic integration. Force-spectroscopy via an atomic-force microscopy was used to guide this development work, which has not been explored previously. Together with accompanying software development and 3D printed molds, an efficient platform for sensor enriched microfluidic devices is developed. It is shown that low-cost and scalable capacitors that can be printed on flexible media and glass can be adapted to detect multiple physical and chemical parameters. Starting from an analytical approximation of printed IDC and fully utilizing the dielectric loading effect, novel sensors were designed and developed for a variety of sensing modalities including proximity and motion, temperature, humidity, electro-kinetic flow, ionic concentrations (proton and divalent metal ions such as Zn, Cu, Ni) in unique microfluidic designs. Based on these distinct sensing approaches, novel device arrangements that include cross-shaped IDCs on flexible paper surfaces, or nanogap capacitors with ~10nm electrode gaps have been adapted as effective and suitable sensing elements in future applications. Thus, this research work provides both principle and practical basis for development of highly capable and flexible capacitive sensing platforms in an upcoming era where effective use of computational resources and CMOS compatibility may become the key enabler for environmental, chemical and biomedical monitoring systems.
Savas Kaya (Advisor)
Wojciech Jadwisienczak (Committee Member)
Avinash Karanth (Committee Member)
Monica Burdick (Committee Member)
David Tees (Committee Member)
Craig Nunemaker (Committee Member)
228 p.
Electrical Engineering
Microfluidics; Lab-on-a-chip; Capacitive Sensors; IDC; Surface Activation; Sensor Fusion

Recommended Citations

Citations

  • Rajan, P. (2019). Novel Capacitive Sensors for Chemical and Physical Monitoring in Microfluidic Devices [Doctoral dissertation, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1549449776383119

    APA Style (7th edition)

  • Rajan, Parthiban. Novel Capacitive Sensors for Chemical and Physical Monitoring in Microfluidic Devices. 2019. Ohio University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1549449776383119.

    MLA Style (8th edition)

  • Rajan, Parthiban. "Novel Capacitive Sensors for Chemical and Physical Monitoring in Microfluidic Devices." Doctoral dissertation, Ohio University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1549449776383119

    Chicago Manual of Style (17th edition)

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This open access ETD is published by Ohio University and OhioLINK.