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Development and analysis of potential nano sensor communication networks based on carbon nanotubes

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  • Save International Journal of M aterials Engineering 2013, 3(1): 4-10 DOI: 10.5923/j.ijme.20130301.02 Development and Analysis of a Potential Nanosensor Communication Network Using Carbon Nanotubes Brian E. Usibe*, Alexander I. Menkiti, Michael U. Onuu, Julie C. Ogbulezie Department of Physics, University of Calabar, P.M .B.1115 Calabar, Nigeria Abstract Nanosensor Technology and Electro magnetic Co mmunications among Nanosensors using the Terahertz (THz) frequency band were examined. An algorith m to show how a Nanosensor node detects a signal was developed using an interpolating network model. In addit ion, a Nanosensor PC Simulator was designed using JCreator LE Setup, to demonstrate the working process of a Wireless Nanosensor Co mmunication Network in a “sensor field”. The findings show that with the introduction of Graphene-based Nanoantennas and Electro magnetic Nanotransceivers, using Carbon Nanotubes (CNTs), nanosensor devices can communicate among themselves in the THz frequency (0.1 – 10) THz. Keywords Co mmun ication Nanosensor, Carbon nanotube, WNSN, Jcreator PC Simu lator 1. Introduction Overview of nanotechnology Nanotechnology is the creation and use of materials or devices at extre me ly sma ll scales. These materials or devices fall in the range of 1 to 100 nano meter (n m). Dimensional range of 1 to 100n m is referred to as the nanoscale and materials at this scale are called nanomaterials. At these dimensions (nm), materials exhib it d ifferent physical properties and behaviours not observed at microscopic level. Thus, many effects at the nanoscale have been discovered and used for breakthrough technologies. Therefore, the aim of nanotechnology is to create nano-devices with new functionalities stemming fro m these unique characteristics. (Yang and Lu zzi, 2009). 1.1. Nanosensor Technolog y One of the early applications of nanotechnology is in the field of sensors and nanosensors. A sensor is a device that measures a physical quantity and converts it into a signal that can be read by an observer (Dan et al, 2004). Nanosensors are biological, chemical or surgical sensory points used to convey informat ion about nanoparticles to the macroscopic world. Nanosensors can be classified based on what they sense. Physical nanosensors measure magn itudes such as mass, pressure, force or displacement. Chemical nanosensors measure magnitudes such as the concentration of a given gas, the presence of a specific type of mo lecule or molecu lar composition of a substance. Biologica l nanosensors are used * Corresponding author: (Brian E. Usibe) Published online at Copyright © 2013 Scientific & Academic Publishing. All Rights Reserved to monitor bio-mo lecular processes such as antibody/antigen interaction, DNA interaction, enzy matic interaction or cellu lar co mmun ication processes (Sukesh, 2007). Nanosensors, as an application of nanotechnology, are extremely important for environ mental, med ical, security and communication applications. Co mmunication among nanosensors will e xpand the capabilities and applications of individual nano-devices, both in terms of co mp lexity and range of operation. Two main alternatives for co mmunicat ion in the nanoscale are; nano-electromagnetic commun ication and molecular communicat ion. Nano-electro magnetic co mmunicat ion is the transmission and reception of electromagnetic radiation fro m co mponents based on novel nanomaterials, wh ile mo lecular co mmun ication is the transmission and reception of information encoded in mo lecules (Aky ildiz and Jornet, 2010). 2. Theory 2.1. Princi ple of operation of a Communication Na nos ens or A particle that is able to sense physical or environmental properties at the nanoscale is known as a nanosensor (Neeraj et al., 2011). So, such a device is assumed able to sense properties of environmental conditions at very small and gaseous levels. A nanosensor therefore has unique properties of nanomaterials and nanoparticles to detect different events in the nanoscale. Nanosensors work with the special sensation ability, which can detect informat ion and data. The arrangement is similar to the ordinary sensors, but their difference is that nanosensors are developed at the n an os cale. International Journal of M aterials Engineering 2013, 3(1): 4-10 5 A nanosensor is useful for co mmunication when it has a sensing unit, actuation unit, power unit, processing unit, storage unit and communication unit. In this type of communicat ion network, the nanosensing unit is co mbined with zinc II o xide (ZnO)-based memo ry due to its reliab ility and repeated switching ability. Thus, after the co mbination of these two types of sensors, the network would have strong sensing ability at the nanoscale and communicating capability through wireless sensor network (WSN). Electro magnetic (EM ) co mmunication among nanoscale devices is enabled by the usage of novel nanomaterials such as graphene in the development of radio frequency nano-transceivers and corresponding electromagnetic nano-antennas, which are few hundreds of nanometers in size. The EM properties observed in these materials determine the specific frequency bands for emission of EM radiation, the time lag of the emission and the magnitude of the emitted power for a given input energy, amongst others. 2.2. Nanoantennas A nanoantenna also known as nantenna is an electro magnetic collector designed to absorb specific wavelengths that are proportional to the size of the nanoantenna. Based on the antenna theory a nanoantenna can absorb any wavelength of signals efficiently, provided the size of the nanoatenna is optimized for that specific wavelength. Ideally, nanoantennas would be used to absorb light at wavelengths between 0.4-1.6μm because these wavelengths have high energy (Corkish et al., 2003). 2.3. Electromagnetic Nanotransceivers The EM transceivers of a nanosensor device would embed the necessary circuitry to perform base band processing, frequency conversion, filtering and power amplification of the signals that have been transmitted or that have been received fro m free-space through the nanoantenna. Taking into account that the nanoantennas would resonate at frequencies in the terahertz band, Radio Frequency Field Effect Transistors (RF FET) able to operate at these very high frequencies are needed. IBM Corp. has recently announced the first RF t ransistor made with graphene that is able to switch at 100GHz (Wang, 2009). 3. Materials Used for Nanosensor Generally, many materials such as gold (for its high detection abilities nano-level) can be used, however, fro m the wireless nano-communication point of view; Carbon Nanotubes (CNTs) with their electrical and mechanical properties are ideal candidates for the development of n an os ens o rs . 3.1. Carbon Nanotubes (CNTs) CNTs are allotropes of carbon with a cylindrical nanostructure. These cylindrical carbon mo lecules have novel properties, making them useful in many applications in nanotechnology, electronics, optics and other fields of materials science. They exhibit extraord inary strength and unique electrical properties and are efficient thermal co n d u cto rs . The band gap of carbon nanotube is directly affected by its chirality and d iameter. If those properties can be controlled, CNTs would be the best candidate for nano-scale transistor d ev ices . The way the graphene sheet is wrapped is represented by a pair of indices (n, m) called the chiral vector. The integers n and m denote the number of unit vectors along two directions in the “honey comb” crystal lattice of graphene. If m=0, the nanotubes are called zig zag. If n = m, the nanotubes are called armchair. Otherwise, they are called chiral (Martel et al., 2001). The diameter of a nanotube can be calcu lated fro m its (n, m) indices by using the exp ression of equation 1 below; d = a n2 + nm + m2 (1) π Where a = 0.246n m (distance between each crystal lattice–unit vector of graphene in real space). Figure 1 shows the unit vectors along two directions in the crystal lattice of graphene. The unique properties of CNTs include; (1) Strength: CNTs are the strongest and stiffest materia ls yet discovered in terms of tensile strength and elastic modulus, respectively. This strength results from the covalent bond formed between the indiv idual Carbon atoms. In 2000, a MWNT was tested and found to have a tensile strength of 63GPa. Th is has the ability to endure tension of a weight equivalent to 6422Kg on a cable with sectional area of 1mm2 (Yu et al., 2000). (2) Hardness: Jensen et al, in 2007 measured the hardness of a SWNT and asserted that it can withstand a pressure of 24GPa without deformation. Maximu m pressure measured using current experimental techniques are around 55GPa. (3) Electrical property: Due to the symmetry and unique electronic structure of graphene, the structure of a nanotube strongly affects its electrical propert ies. For a g iven (n, m) nanotube, if n = m, the nanotube is metallic, if n > m is a mu ltip le of 3, then the nanotube is semi-conducting with a very small band gap, otherwise the nanotube is a moderate semiconductor. Thus, all armchair types (n = m) are metallic and nanotubes (6, 4), (9, 1), etc are semi-conducting. Because of the strong covalent carbon-carbon bonding, carbon nanotubes are chemically inert and are able to transport large amounts of electric current (Fran z, et al 2002). (4) Thermal property: All nanotubes are expected to be very good thermal conductors along the tube, exhib iting a property known as “ballistic conduction”, but good insulators laterally to the tube axis. In theory, carbon nanotubes are also able to conduct heat nearly as well as diamond or sapphire. Measurements show that a SWNT has a room temperature thermal conductivity of 3500W m-1 K-1 along its axis (Pop et al., 2005). The temperature stability of 6 Brian E. Usibe et al.: Development and Analysis of a Potential Nanosensor Communication Network Using Carbon Nanotubes CNT is estimated to be up to 2800℃ in vacuu m and about 750℃ in air (Thostenson et al., 2005). (5) Defects: As with any material, the existence of a crystallographic defect affects the material’s properties. Defects can occur in the form of ato mic vacancies. High levels of such defects can lower the tensile strength by up to 85% . (6) 1-D trans port: CNTs are also quasi-1D materials in which only forward scattering is allo wed. Because of the nanoscale dimensions, electrons propagate only along the tube’s axis and electron transport involves many quantum effects . 4. Discussions 4.1. Nanosensor Architecture and Wireless Network A nanosensor network should be composed of a large number of nanosensor nodes that are densely deployed. Nanosensor nodes are scattered in a special domain called “sensor field”. Each of the distributed nodes equipped with a graphene-based nanoantenna typically has the capability to communicate with their neighbours, collect data, analy ze them and route them to the des ignated s ink point. Inorder to turn existing nanosensors into autonomous devices that can create a network, it is necessary to embed them with additional functionalities such as power source, processing capabilities and onboard storage. The sensing range of a single nanosensor is limited to its close environment. However, a wireless nanosensor network (WNSN) would be able to cover large areas, reach unprecedented locations in a non-invasive way and perform in-networking processing and cooperative actuation. A single nanosensor device, sensing or detecting a relevant event would commun icate with its neighbours and transmit the information in a mu lti-hop (tree topology) fashion to a sink or co mmand centre, wh ich will connect with the mac ro-world and the fina l users. Furthermore, their communicat ion capabilities would allow them to receive commands fro m other devices to either change behaviour or actuate, as the case may be. The co mponents of a typical sensing node are shown in figure 2 4.2. Enhancement of signals One of the essential attributes of a nanosensor is that it should be able to detect minute quantities of an analyte. However, at those atomic scales, the issue of signal enhancement should be addressed. The enhancement of signals may be done using frequency mu ltip liers such as Gunn diodes, IMPATT (Impact Ionizat ion Avalanche Transit-Time) diodes and Schottky diodes. The operation is based on the application of wave whose frequency is a fraction of the desired frequency to a non-linear circu it that distorts the input signal and consequently its harmonics are generated in the device. A subsequent band pass filter selects the desired harmon ic frequency and removes the unwanted fundamental and other harmonics fro m the output. Figure 3 shows the block diagram fo r frequency mult iplication. 4.3. Applications of Wireless Nanosensor Networks The applications of wireless nanosensor networks (WNSNs) are broadly classified into environmental, medical, military and industrial. Environmental Applicati ons Traditionally, sensor networks are used in the context of high environmental applications such as radiation and nuclear threat detection systems, weather sensing, habitat sensing and seismic monitoring. Other potential applications include, microclimates, forest fire detection and flood detection. Chemical-physical-acoustic and image based sensors can be utilized to study ecosystems (examp le, in support of global parameters such as temperature and population of microorganis ms) (Sohraby et al., 2007). However, the high sensibility and the large diversity of chemical nanosensors can be exploited in other environmental applicat ions such as precision agricu lture (plant monitoring and plagues defeating systems). Precision farming, also known as site-specific management describes a bundle of new Informat ion Technologies applied to management of large-scale co mmercial agriculture. Precision farming relies upon intensive sensing of environmental conditions and Co mputer processing of resulting data to inform decision making and control farm mach inery. This technology typically connects Global Positioning System (GPS) with satellite imaging of fields to remotely sense crop pests or evidence of drought and then automatically adjust levels of irrigation or pesticide application. If the network of Wireless Nanosensors function as designed, ubiquitous wireless sensors will become an essential tool for b ringing this vision of precision farming to maturity. Medical Applicati ons Biological nanosensors provide an interface between biological phenomena and electronic nano-devices. Wireless nanosensor networks have potential application in Remote Monitoring of Physiological Data. Remote Monitoring of Physiological Data The presence of different infectious agents in the body can be monitored by means of nanosensors. In addition, the level of cholesterol, sodium, glucose and other ions in the blood can be monitored. For examp le, tattoo-like sensors (fluorescent ion-selective nanosensors for intracellular analysis) can be used to monitor glucose level in blood, etc. Figure 4 shows different nanosensors distributed around the body, defining a human body nanosensor network that can be used to gather data about the level of different s u bstan ces . A wireless interface between these nanosensors and a micro -device such as a cellphone or specialized medical International Journal of M aterials Engineering 2013, 3(1): 4-10 7 equipment (gateway) could be used to collect all these data and forward them to the healthcare provider through the internet. Military Applications Self-organization ability and fault tolerant characteristics of WNSNs make them versatile for military applications such as: (1) Nuclear, bio logical and chemical attack detection (2) Battlefield surveillance: Monitoring of in imical and friendly forces. (3) Armour damage detection. (1) Nuclear, Biological and Chemical Attack Detection Chemical and bio logical nanosensors can be used to detect harmful chemical/bio logical weapons in a distributed manner. One of the ma in benefits of using nanosensors rather than classical chemical sensors is that the presence of a chemical co mposite can be detected in a concentration as low as one molecu le. However, taking into account that these sensors need direct contact with the molecules, having a network with a very large nu mber of nanosensor node is necessary. In addition, by means of che mica l nanosensors, it is possible to recover the mo lecular co mposition of a battlefield without requiring external and large equip ments such as devices used for spectroscopy. A WNSN will be able to convey the informat ion of the mo lecular co mposition of the air in a specific location to a macro-device within a very short time. (2) B attle Fiel d Surveillance: Moni toring Ini mical and Friendl y Forces On the battlefield, nanosensors can be used to identify and/or attract friendly or in imical objects, vehicles, aircraft and personnel (soldiers). Sensor nodes can be deployed on a battlefield, in front of or beyond enemy lines. Here, a system of networked nanosensors can detect and attract threats and be utilized for weapon targeting and area denial. So ldiers covered with nanosensors would submit data to remote servers where monitoring agents will be able to know the status of soldiers in the battlefield. (3) Armour Damage Detecti on Physical nanosensors can be used to detect very small cracks in text iles, civil structures (bridges, buildings), vehicles, etc. By having a network of nanosensors distributed over the structures that have to be monitored and by means of interaction with micro or macro devices, WNSNs can be used to detect, the origin of problems in functionalized soldiers’ armour and other structures exposed to attacks. Industrial and Commercial Applications Industrial and commercial applications include, but are not limited to, Future Interconnected Office (FIO) application. Future Interconnected Office The interconnection of nanosensor and nano-actuator devices with existing commun ication networks and ultimately the internet enables new interesting applications that will in fluence how offices operate. Fo r example, in an interconnected office, every single element can be permanently connected to the internet. As a result, a user can keep track of all pro fessional belongings, as well as assets and liabilit ies management. Figure 5 illustrates the architecture for a future interconnected office. 5. Results Algorithm for nanosensor applicati on using interpol ati on network model Using the medical field as an examp le, a guide as to how the capabilit ies of a nanosensor senses a signal and communicates it to its neighbours located in a sensor field is illustrated using the algorithm below. 001 Defines parameters = primary keys = VAR (A, B, C, D) 002 Primary key parameters VAR (A) = DNA 003 Primary key parameters VAR (B) = Enzy mes 004 Primary key parameters VAR (C) = Antibody 005 Primary key parameters VAR (D) = Antigen 006 Infuse defined parameters VA R (A, B, C, D) in an open source machine. 007 Define an object = secondary parameter = VA R (H) 008 Contact VAR (H) on the open source 009 Enhance object on line 006 010 If the object on line 006 = VA R (A) = DNA 011 Repeat 009 012 End 011 013 Then Go to 017 014 Else Go to 007 015 End 014 016 Repeat 009 until VA R (A, B, C, D) = [VAR (H)]; [VA R (B)]; [VA R (C)]; (VA R (D)] 017 End 016; for VA R (A, B, C, D) = ([DNA; Enzy mes; Antibody; Antigen]) 018 End 009 A navigation on the intra-network system on mother nanosensor unto,, etc displays the results of line 016 of the algorithm/Program on all the sensors within the defined area (Sensor field), with demonstrated simu lation using computer systems. Nanosensor PC Simulator Nanosensor PC simu lator is an application software designed to simu late the wo rking process in a communicat ion nanosensor network. The simulator has two components; PC Mother Sensor viewer that runs on the computer system that serves as the server and the Nanosensor PC that runs on the computer that serves as the host/node. The PC Mother sensor detects and displays the attributes of all Nanosensor PCs on a wireless network configured within the same IP range. If the Mother Sensor Viewer is running on, then all other co mputers on which the Nanosensor PC will run are configured with IP addresses within the range of to, except assigned to the Mother Sensor Viewer. This will establish a protocol that forms the basis for their communicat ion. 8 Brian E. Usibe et al.: Development and Analysis of a Potential Nanosensor Communication Network Using Carbon Nanotubes The Nanosensor PC is a co mponent of the application that runs on any computer in a wireless environment. Whenever the Nanosensor PC runs, it displays its properties on its panel and waits for the Mother Sensor Viewer’s request. As soon as the Viewer requests for its properties, it sends themon any computer provided it is running the same applicat ion and on the same network. Figure 1. The (n,m) nanotube-naming scheme thought of as a unit vector (Ch) in an infinite graphene sheet that describes howto “roll up” a graphene sheet to form nanotubes Communication Unit Sensing Unit Nano-sensor ADC Sensing Unit Nano- sensor ADC Processing Unit Processor Storage Nano- transceiver Power Unit Location finding system Power Generator Actuation Unit Figure 2. Typical nanosensor node (Zhang, 2004) Non-Linear ωο Device nωο Figure 3. Process of frequency multiplication for signal enhancement. Where ωο is the frequency to be multiplied, nωο is the number times, the frequency is multiplied International Journal of M aterials Engineering 2013, 3(1): 4-10 9 Internet Macro-link Micro -link Gateway Nano-link Nano-nodes Healthcare provider Nano-micro Interface Nano-router Fi gure 4. Architect ure for Wireless Nanosensor Net works in health applicat ion Source: Broadband Wireless Networking Laboratory, School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta Georgia, USA Figure 5. Architecture for a future interconnected office 6. Conclusions Nanotechnology is enabling the develop ment of devices in a scale ranging fro m one to a few hundred nanometres. One of the pro mising applications of this technology is in the field of sensing. A nanosensor is not only a tiny sensor, but also a device that makes use of novel properties of nanomaterials, especially carbon nanotubes (CNTs) to detect and measure new types of events in the nanoscale, employing carbon-based EM nanotransceivers and nanoantennas. However, the sensing range of a single nanosensor is limited to its close environ ment and thus many nanosensors are needed to create a netwo rk. The development of an integrated nanosensor device with communication capabilit ies will overco me the limitations of indiv idual nanosensors and expand their potential applicat ions. The working process of a Wireless Nanosensor Co mmunicat ion Network is illustrated using an interpolating algorith m to show how a Nanosensor node detects a signal. In addition, a Nanosensor PC Simu lator was designed using JCreator LE Setup to demonstrate signal exchange in a WNSN. REFERENCES [1] Akyildiz, I. F. and Jornet, J. M : Electromagnetic wireless nanosensor networks. (2010) [2] Corkish, R. et al.: Solar ener gy collection of Antennas. (2003) Elsevier Science Ltd. [3] Dan, P. et al.: Nanosensors and devices for space and terrestrial applications. (2004) CRC press, Boca Raton, USA. [4] Franz, K. et al. Carbon nanotubes for interconnect applications. Physical Review Letter (2002). 64, 399-408. [5] M artel, R. et al. Am-bipolar electrical transport in semiconducting single-walled carbon nanotubes. Physical Review Letter. (2001) 87, 25. 10 Brian E. Usibe et al.: Development and Analysis of a Potential Nanosensor Communication Network Using Carbon Nanotubes [6] Neeraj, K. et al. A novel approach to use nanosensor in [11] Walter, E. C. et al. Sensor from electrodeposited metal wireless sensor network application. International Journal of nanowire. Surface and Interface. (2002) John Wiley & Sons Computer Application (2011) Vol 14, No 11. Ltd. [7] Pop, E. et al. Thermal conductance of an individual single-walled carbon nanotube films. Journal of Nanoparticles Research above Room Temperature. Nano Letters. (2005) 6, 1. [8] Sohraby, K. et al: Wireless sensor network: Technology, Protocols and Applications. (2007)John Wiley & Sons Ltd. [9] Sukesh, S. Design, simulation and analysis of a molecular nanosensor for energetic materials. Unpublished M .Sc Thesis. Graduate School, Texas A & M University. (2007) [10] Thostenson, E. et al. “Nano-composites in context” Composites Science and Technology (2005) 3, 4. [12] Wang, H. et al. Graphene frequency multipliers, IEEE Electron Device Letters. (2009) 30, 5. [13] Yang, P. and Luzzi, E. “Nanotechnology” (2009) M icrosoft Encarta DVD. [14] Yu, M . et al. Strength and breaking mechanism of multi-walled carbon nanotubes under tensile load. (2000) Science M agazine. [15] Zhang, Z. Wireless communication protocol architecture for nanosensor network. Archival M aterial. University of Alaska. (2004)

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