The aim behind the development of nanogenerators is to partially solve the issue of the energy crisis and the creation of self-powered sensors and systems. The TENG is a discontinuous source of energy, so it was coupled with the energy storage and power management units to achieve the applications that require continuous output. The sustainable power source like TENG is of great need as the current market is dominated by batteries, which are difficult to recycle.
Furthermore, in the case of implantable devices like a pacemaker, the battery needs to be replaced by the surgery, which created not only financial suffering but also creates physical suffering to the patients. The advantages of the TENG led to its exploration as a power source for a wide range of applications. The TENG is reported for a wide range of applications like biological sensors,
18 chemical sensors, drug delivery, cell modulation, biodegradable power source, physical sensors, blue energy harvesting, smart buoy, intrusion monitoring, etc. [8, 18, 23, 51, 54, 55]. Few of the applications of TENG are summarized in Figure 1.11. However, several issues need to be addressed before the commercialization of TENG.
Figure 1.11. Applications of TENG.
19 1.9 Objective and scope of the thesis
The growing population raises the issue of energy crisis as natural resources to take thousand of years to replenish. Moreover, the burning of natural fuels is a threat to the environment.
Hence, the focus shift towards to development of portable energy harvesting devices to partially solve the issue. The TENG is one such energy harvesting device with easy fabrication and a wide range of available device designs. The thesis starts with the origin and the fundamentals of TENG.
The first part of the thesis is based on the literature review where, three main aspects (sustainable devices, the device for chemical sensing, and biodegradable device) are explored to gain the necessary understanding. During the process, the main lag found in the research is the materials available in the triboelectric series for the fabrication of TENG. The triboelectric series predominantly consists of polymers and few metals, which are challenging to modify and functionalize. The applications requiring high selectivity and specificity is thus hard to achieve with the available materials. The multifunctional materials with tunable properties are highly desirable for extending the triboelectric series and application of TENG. The MOF is one such class of material that is not explored for the TENG. The MOF, composed of a metal ion coordinated with an organic ligand. The porous structure of the MOF provides a high surface area to improve the functionality of TENG devices. Thus, careful selection of the MOF component can yield a crystal framework with high porosity and high chemical and thermal stability. So, the main focus of the thesis is to explore the various MOF for their contact-electrification behavior, potential in the field of TENG, and self-powered sensor. The objectives of the thesis are described below
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➢ To understand the basics of TENG by studying the sustainable device, a device for chemical sensing, and biodegradable devices.
➢ To fabricate all waste material (trash to energy) based device.
➢ To demonstrate the in-house fabrication by using the day to day life waste materials.
➢ To demonstrate the essential applications to give an idea for the utilization of TENG for a layman.
➢ To fabricate an enhanced output TENG for chemical sensing application.
➢ To fabricate all edible material based biodegradable and biocompatible device.
➢ To study cytotoxicity of the edible TENG device.
➢ To fabricate the large size device to demonstrate the suitability of the materials for scale-up.
➢ To synthesize ZIF family member ZIF-7, ZIF-9, ZIF-11, and ZIF-12 at room temperature by a wet chemical approach.
➢ To synthesize mixed linker framework ZIF-62 by hydrothermal route.
➢ To grow ZIF-8 for different cycles on conducting ITO coated PET substrate by using the solution growth process.
➢ To synthesize MBIOF using a wet chemical approach.
➢ To investigate the formation of the materials by employing various characterization tools and techniques.
➢ To study the contact-electrification behavior of the ZIF family members, ZIF-62, ZIF-8, and MBIOF.
➢ To study the surface roughness and surface potential behavior of the different MOF material.
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➢ To coat and demonstrate the scale-up of MBIOF coating using simple tape cast coater on various substrates.
➢ To study cytotoxicity of MBIOF on dermal fibroblasts and mammary epithelial cells.
➢ To study the stability of the MBIOF coating.
➢ To study the electrical performance of the fabricated TENG devices by using the different MOF materials.
➢ To study the effect of the ZIF-8 growth cycles on the output performance of the C-S mode TENG.
➢ To power up various low-power electronics like calculator, UV LEDs, IR LEDs, etc. using the ZIF-7 TENG device.
➢ To demonstrate the ZIF-62 TENG device for fitness tracking while performing various gym exercises.
➢ To demonstrate the UV currency counterfeit system using the ZIF-8 TENG device.
➢ To demonstrate the selective, specific, and reusable tetracycline sensor using ZIF-8 TENG.
➢ To demonstrate the MBIOF based TENG for self-powered hydrogen peroxide sensor.