Sang-Jae Kim

By Gunasekaran Venugopal, Shrikant Saini and Sang-Jae Kim

Part of the book: Micromachining Techniques for Fabrication of Micro and Nano Structures

By Gunasekaran Venugopal and Sang-Jae Kim

Part of the book: Advances in Micro/Nano Electromechanical Systems and Fabrication Technologies

By Nagamalleswara Rao Alluri, Arunkumar Chanderashkear and Sang- Jae Kim

Smart energy harvesting through the surrounding environment generates sufficient energy to drive the low-power consumption systems. It is the forthcoming revolution in smart (or self-powered) technology and results in abolishing the usage of complex batteries, external circuit components, and natural sources. To date, extensive fabrication methods, the growth of ZnO nanostructures on plastic substrates, and flexible piezoelectric polymer film-based devices were tested to improve the performance of piezoelectric nanogenerator (PNG) as a prominent energy-harnessing approach for the development of sustainable independent power sources. Still, PNG technology suffers from brittleness, leakage current issues, high electrical output generation, and long-term durability, which can be possible to control by the composite technology, that is, polymer/nanoparticles. The objective of this book chapter determines the rapid growth of multifunctional, flexible composite structures through various methods (e.g., ionotropic gelation method, groove technique, ultrasonication followed by solution-casting methods) for high output energy generation and self-powered sensor/system studies.

Part of the book: Energy Harvesting

By Ananthakumar Ramadoss, Balasubramaniam Saravanakumar and Sang-Jae Kim

Ever increasing energy demand urges to impelled extensive research in the development of new eco-friendly energy harvesting and storage technologies. Energy harvesting technology exploiting renewable energy sources is an auspicious method for sustainable, autonomous, and everlasting operation of a variety of electronic devices. A new concept of an integrated self-powered system by combining an energy harvesting device with an energy storage device has been established to harvest renewable energy and simultaneously store it for sustainable operation of electronic devices. In this chapter, describes the fabrication of a self-powered system by integrating the supercapacitor with energy harvesting devices such as nanogenerator and solar cells to power portable electronic devices. Initially synthesis and electrochemical characterization of various electroactive materials for supercapacitors and further, fabrication of supercapacitor device were discussed. In conclusion, this chapter demonstrates self-powered system by the integration of energy harvesting, energy storage module with portable electronic devices. The various result validates the feasibility of using supercapacitors as efficient energy storage components in self-powered devices. The proposed self-powered technology based on energy conversion of renewable energy to electrical energy which stored in energy storage device and it will be used to operate several electronic devices as a self-powered device.

Part of the book: Advancements in Energy Storage Technologies

By Venkateswaran Vivekananthan, Arunkumar Chandrasekhar, Nagamalleswara Rao Alluri, Yuvasree Purusothaman, Gaurav Khandelwal and Sang-Jae Kim

Scavenging energy from our day-to-day activity into useful electrical energy be the best solution to solve the energy crisis. This concept entirely reduces the usage of batteries, which have a complex issue in recycling and disposal. For electrical harvesting energy from vibration energy, there are few energy harvesters available, but the fabrication, implementation, and maintenances are quite complicated. Triboelectric nanogenerators (TENG) having the advantage of accessible design, less fabrication cost, and high energy efficiency can replace the battery in low-power electronic devices. TENGs can operate in various working modes such as contact-separation mode, sliding mode, single-electrode mode, and free-standing mode. The design of TENGs with the respective operating modes employed in generating electric power as well as can be utilized as a portable and wearable power source. The fabrication of triboelectric layers with micro-roughness could enhance the triboelectric charge generation. The objective of this chapter is to deal with the design of triboelectric layers, creating micro structured roughness using the soft-lithographic technique, fabrication of TENGs using different working modes, energy harvesting performance analysis, powering up commercial devices (LEDs, displays, and capacitors), and portable-wearable applications.

Part of the book: Nanogenerators

By Parthiban Pazhamalai, Karthikeyan Krishnamoorthy and Sang-Jae Kim

This book chapter discusses the topochemical synthesis of blue titanium oxide (b-TiO2) and their application as electrode material for supercapacitor devices in aqueous and organic electrolytes. The formation mechanism of b-TiO2 via topochemical synthesis and their characterization using X-ray diffraction, UV–visible, photoluminescence, electron spin resonance spectroscopy, laser Raman spectrum, X-ray photoelectron spectroscopy, and morphological studies (FESEM and HR-TEM) are discussed in detail. The supercapacitive properties of b-TiO2 electrode were studied using both aqueous (Na2SO4) and organic (TEABF4) electrolytes. The b-TiO2 based symmetric-type supercapacitor (SC) device using TEABF4 works over a wide voltage window (3 V) and delivered a high specific capacitance (3.58 mF cm−2), possess high energy density (3.22 μWh cm−2) and power density (8.06 mW cm−2) with excellent cyclic stability over 10,000 cycles. Collectively, this chapter highlighted the use of b-TiO2 sheets as an advanced electrode for 3.0 V supercapacitors.

Part of the book: 21st Century Nanostructured Materials