The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	Flexible microfluidic device with nonplanar interdigitated microelectrodes
Author:	Alssaidy, Saud
View Online:	njit-etd2021-057 (ix, 26 pages ~ 1.5 MB pdf)
Department:	Department of Chemical and Materials Engineering
Degree:	Master of Science
Program:	Materials Science and Engineering
Document Type:	Thesis
Advisory Committee:	Basuray, S. (Committee chair) Voronov, Roman S. (Committee member) Armenante, Piero M. (Committee member)
Date:	2021-12
Keywords:	Packed flexible 3d nonplanar interdigitated microelectrodes Wearable microfluidic sensors Lithography and deposition process Sensors sensitivity Flexible microfluidic sensors Embedded system
Availability:	Unrestricted
Abstract:	The lab-on-a-chip concept has improved significantly in recent years to meet global demand for various applications with the advent of new technologies. Much progress has been achieved, but many microfluidic devices still suffer from design limitations in terms of sensitivity and selectivity because they use rigid, fragile substrate materials and conventional electrodes, which do not provide high sensitivity or selectivity and suffer from signal-to-noise ratio issues. This work proposes a novel device architecture that uses flexible, transparent top and bottom layers integrated with (nonplanar interdigitated microelectrodes) to create a sandwich-like flexible substrate base. The top and bottom layers consist of 3D nonplanar interdigitated microelectrodes developed using soft lithography and deposited over transparent flexible materials such as polydimethylsiloxane, polyethylene terephthalate, or polybutylene adipate terephthalate (e.g., eco flex) Polyethylene terephthalate (PET). We created the middle layer composed of microfluidic channels using flexible polypropylene double-sided adhesive layer tape. This device's design, which involves nonplanar interdigitated microelectrodes over transparent flexible and stretchable material and flexible microfluidic channels, provides the following advantages over conventional devices: (a) a flexible design involving flexible materials that make it wearable and could be used in embedded systems and (b) high sensitivity resulting from nonplanar microelectrodes with different configurations that improve the electric field in the microfluidic channels. Furthermore, we can use various materials in the microfluidic channels, such as metal-organic-framework (MOF), as transducers to improve the signal-to-noise ratio, sensitivity, and selectivity. We also show that optical and electrochemical methods such as CV, EIS, and DPV could create a multipurpose device and embedded system. Finally, we show the device's sensitivity and selectivity limits.