Name: RAVI TEJA Y S SIDDHANT MISHRA Affiliation: Progressive Engineering college Progressive Engineering College Branch: B tech IInd year B tech IInd year Electronics and Communications Electronics and Communications
Author: RAVITEJA Y S SIDDHANT MISHRA Affiliation: Progressive Engineering College Progressive Engineering College Branch: Electronics and Communication Electronics and Communication ABSTRACT:
Nano generator is an extremely small device that is capable of generating electric current, electromagnetic fields. Generally in power systems the word ‘generator’ gives an impression of huge, mechanic and bulk in one’s mind. Time has come to unleash the new era of generators. So, Nano generator is one such concept which is very small in size and solves the purpose of generating energy and can be alternate to present generators. The Nano generators produce the required “output” by the elongation of Nano wires starting from size 5 nanometers between a zigzag electrode and substrate(solid or flexible) by the application of sonic waves or mechanical vibrations.. The application of tension i.e. stretching and straining of Nano wires results in the flow of electric charge. The Nano generator with optimization could produce as much as 4 watts per cubic centimeter based on a calculation for a single Nano wire.. Advantages of the Nano generators are small size, efficient, large scale production and portable. By converting mechanical energy from body movement, muscle stretching or water flow into electricity, these "Nano generators" can make it possible to emerge into a new class of self-powered implantable medical devices, sensors and portable electronics. There is no surprising thing that you can just charge your iPods and mobile phones just by a stroll. This paper gives an overview what exactly is a Nano generator and its capabilities, its advantages and applications.
The world has taken a new phase in Nano technology. There is a drastic change in the field of power systems. Researchers have developed a new technique for powering nanometer-scale devices without the need for bulky energy sources such as batteries. By converting mechanical energy from body movement, muscle stretching or water flow into electricity, these "nanogenerators" could make possible a new class of self-powered implantable medical devices, sensors and portable electronics. The name ‘Nano generators’ is given considering its size. In Latin the word Nano means “dwarf” and the generators are defined as the device which converts mechanical energy in to electric energy considering the faradays laws.
Image 1: Present Generators.
The above image features present generators, the impression on one’s mind is its huge, mechanic and bulky. This heavy size makes them non portable, needs high maintenance and highly sonorous.
. Image 2: Nano Generator
Here in this picture a 2µm size Nano generator placed over a button which is held by a forceps is shown. Now this gives an exact idea of Nano generator.
The novel approach to building a Nano generator is composed of integrated, paired Nano brushes made of pyramid-shaped metal-coated zinc oxide Nano tip arrays and hexagonal prism-shaped zinc oxide Nano wire arrays, which were synthesized using a chemical approach on the two surfaces of a common substrate, respectively" "When one piece of this structure is stacked in close proximity over another to form a layer-by-layer matched brush architecture, direct current is generated by exciting the architecture using ultrasonic waves. A four-layer integrated Nano generator is demonstrated to generate an output power density of 0.11 µW per square centimeter at a voltage of 62 mV." This approach can bring rapid change in the revolution of power systems.
An Innovative approach for converting Nano-scale mechanical energy into electric energy by piezoelectric zinc oxide Nano wire (NW) arrays. The operation mechanism of the electric generator relies on the unique coupling of piezoelectric and semi conducting dual properties of ZnO as well as the elegant rectifying function of the Schottky barrier formed between the metal tip and the NW. Based on this mechanism, we have recently developed DC Nano generator driven by ultrasonic wave in Bio-Fluid. The use of textile fibers for energy harvesting introduced the fundamental principle of Nano generator and its potential applications. Finally, a new field on Nano piezotronics is introduced, which uses piezoelectric-semi conducting coupled property for fabricating novel.
Image 3: Nano Wire.
The mechanism of Nano generator is based on a piezoelectric effect. ‘Piezoelectric’ the generation of Electric charge by certain materials, when a force is applied, or conversely the deformation of the material when a potential is applied. Here an array of Nano wires are placed perpendicular to the substrate (solid or flexible) and then covered by a zigzag electrode.
Image 4: Cross section area of Nano Generator
The zigzag electrode and the substrate is used as the covering material and also serves the purpose of terminals to the Nano generator for collecting charge diffused. The space between these terminals is covered with the waterproof soft material probably a Bio fluid. When the sonic waves or mechanic vibrations are applied to this setting the flow of electric charge takes. The output current from Nano generators is direct current (DC). Now this current is collected between the zigzag electrode and the substrate and in turn given direct supply to the appropriate electronic gadget.
One of the outstanding benefits of this approach is that the Nano wires and Nano tips do not have to be patterned on substrates in order to raise the output current/voltage, which greatly simplifies the fabrication process and cost. The design does not demand that all of the Nano wires and Nano tips have a very uniform height and/or shape, thereby greatly reducing the complexity for sample growth. The operation of the Nano generator relies on mechanical deflection or bending of the Nano wires in which resonance of Nano wires is not required to activate the generator. This largely expands their application from low frequency (in the hertz range) to a relatively high frequency (in the megahertz range) for effectively harvesting mechanical energies in our living environment. The Nano tips and Nano wires were synthesized using a chemical approach at below 100°C. This simple and low-cost technology has an outstanding potential for large-scale application. The layer-by-layer assembly technique that the scientists used provides a feasible technology for building multilayered nanogenerators for applications where force or pressure variation are available, such as a shoe pad, under skin layer for airplanes, and next to a vibration source such as car engine or tire. "In order to power larger devices such as MP3 music players we would need to be able to generate output in the 10-100 mille watt range. Our novel nanogenerators demonstrate a scalable platform for increased power output that would make this possible." APPLICATIONS:
The Nano generators have vast applications in various fields like biological, scientific and also electronics. Nano generators are used in bio sensors and Nano devices as shown in below image 5(a).
Nano generators are used in Microelectromechanical sensors.
Nano generators can also be used to charge your iPod, mp3 players by a stroll of walk. Image 5(b) shows a practical IPod.
 Nano generator book by Georgia Tech Professor Zhong Lin Wang.  Applied Physics by P.K Palaniswami.