Maximizing Efficiency of Large Scale Homogeneous Wireless Sensor Networks

Wireless Sensor Networks is a set of sensors deployed in the area of interest, for the purpose of monitoring physical or environmental conditions. Due to limited battery capacity of sensors, Wireless Sensor Networks have limited lifetime. A large number of sensors deployed in a circular grid, sending the sensed data to base station located at the center are considered and the parameters of interest are monitored. This paper proposes two algorithms to enhance the lifetime, reliability and throughput of the Wireless Sensor Network. The first algorithm Reliable Zone Based Transmission (RZBT) reschedules the packet transmission time of the sensor nodes, to reduce the loss of packets and ensures reliability of network functioning. The second algorithm Energy Efficient Reduced Transmission (EERT) reduces the number of transmissions, without the loss of data, thus extending lifetime of the network. Simulation results prove that RZBT outperforms conventional DiReCT Transmission (DRCT) and EERT reduces the packets transmitted in each round, thus improves the lifetime of the sensor node and the network

Electrostatic Conversion for Vibration Energy Harvesting

This chapter focuses on vibration energy harvesting using electrostatic converters. It synthesizes the various works carried out on electrostatic devices, from concepts, models and up to prototypes, and covers both standard (electret-free) and electret-based electrostatic vibration energy harvesters (VEH).Comment: This is an author-created, un-copyedited version of a chapter accepted for publication in Small-Scale Energy Harvesting, Intech. The definitive version is available online at: http://dx.doi.org/10.5772/51360 Please cite as: S. Boisseau, G. Despesse and B. Ahmed Seddik, Electrostatic Conversion for Vibration Energy Harvesting, Small-Scale Energy Harvesting, Intech, 201

Zone Based Transmissions for Homogeneous Wireless Sensor Networks

—Wireless Sensor Network is a set of sensors deployed in the area of interest, for the purpose of monitoring physical or environmental conditions. Due to limited battery capacity of sensors, Wireless Sensor Networks have limited lifetime. A large number of sensors deployed in a circular grid, sending the sensed data to base station located at the center are considered and the parameters of interest are monitored. This paper proposes three algorithms to enhance the lifetime, reliability and throughput of the Wireless Sensor Network. The first two algorithms Reliable Zone Based Transmission (RZBT) and Reliable Circular Transmission (RCT) reschedule the packet transmission time of the sensor nodes, to reduce the loss of packets and ensures reliability of network functioning. The third algorithm Energy Efficient Reliable Transmission (EERT) reduces the number of transmissions, without the loss of data, thus extending lifetime of the network. Simulation results prove that 1) RCT outperforms conventional DiReCt Transmission (DRCT) and RZBT with respect to throughput and 2) EERT reduces the packets transmitted in each round, thus improves the lifetime of the sensor node and the network

Zone Based Transmissions for Homogeneous Wireless Sensor Networks

Wireless Sensor Network is a set of sensors deployed in the area of interest, for the purpose of monitoring physical or environmental conditions. Due to limited battery capacity of sensors, Wireless Sensor Networks have limited lifetime. A large number of sensors deployed in a circular grid, sending the sensed data to base station located at the center are considered and the parameters of interest are monitored. This paper proposes three algorithms to enhance the lifetime, reliability and throughput of the Wireless Sensor Network. The first two algorithms Reliable Zone Based Transmission (RZBT) and Reliable Circular Transmission (RCT) reschedule the packet transmission time of the sensor nodes, to reduce the loss of packets and ensures reliability of network functioning. The third algorithm Energy Efficient Reliable Transmission (EERT) reduces the number of transmissions, without the loss of data, thus extending lifetime of the network. Simulation results prove that 1) RCT outperforms conventional DiReCt Transmission (DRCT) and RZBT with respect to throughput and 2) EERT reduces the packets transmitted in each round, thus improves the lifetime of the sensor node and the network

An Overview of Distributed Energy-Efficient Topology Control for Wireless Ad Hoc Networks

A wireless ad hoc network is composed of several tiny and inexpensive device such as wireless sensor networks (WSNs) which have limited energy. In this network energy, efficiency is one of the most crucial requirements. Data transmitting in minimum power level is one way of maximizing energy efficiency. Thus, transmission power level of nodes should be managed in a smart way to improve energy efficiency. Topology control is one of the main algorithms used in a wireless network to decrease transmission power level while preserving network connectivity. Topology control could improve energy efficiency by reasonably tuning the transmission power level while preserving network connectivity in order to increase network capacity and lifetime. In pursuit of energy efficiency and connectivity, nodes can be selfish and are conflicting with each other. Therefore to overcome the conflict, game theory is used to construct energy efficient topology, as well as minimizing energy consumption. In this paper, the main goal and most recent energy efficient topology control algorithms in WSNs and ad hoc network are classified and studied according to their specific goals

Improved Unequal-Clustering and Routing Protocol

Increased network lifetime is a desired property of low-powered and energy-constrained Internet of Things (IoT) devices that are deployed in wireless network environments. Clustering is used as a technique in multiple solutions to improve overall network lifetime. Further variants in the clustering process are defined to optimize the results. One such variant is equal clustering, where all the clusters have the same size. However, this approach suffers from the issue of nodes closer to the base station (BS) dying out earlier. As an alternative, unequal clustering is proposed, where clusters close to the BS are of smaller size; thus, cluster heads (CHs) consume a substantial proportion of their energy for being acting as data forwarding nodes. In this paper, we propose an unequal clustering approach with the BS at the center of a circular area. The size of each cluster is fixed and computed based on the node density of the area. The number of clusters increases from outwards to inwards towards the BS. The results show considerable performance gain over selected benchmark works

An energy-efficient mobile sink-based unequal clustering mechanism for WSNs

Network lifetime and energy efficiency are crucial performance metrics used to evaluate wireless sensor networks (WSNs). Decreasing and balancing the energy consumption of nodes can be employed to increase network lifetime. In cluster-based WSNs, one objective of applying clustering is to decrease the energy consumption of the network. In fact, the clustering technique will be considered effective if the energy consumed by sensor nodes decreases after applying clustering, however, this aim will not be achieved if the cluster size is not properly chosen. Therefore, in this paper, the energy consumption of nodes, before clustering, is considered to determine the optimal cluster size. A two-stage Genetic Algorithm (GA) is employed to determine the optimal interval of cluster size and derive the exact value from the interval. Furthermore, the energy hole is an inherent problem which leads to a remarkable decrease in the network’s lifespan. This problem stems from the asynchronous energy depletion of nodes located in different layers of the network. For this reason, we propose Circular Motion of Mobile-Sink with Varied Velocity Algorithm (CM2SV2) to balance the energy consumption ratio of cluster heads (CH). According to the results, these strategies could largely increase the network’s lifetime by decreasing the energy consumption of sensors and balancing the energy consumption among CHs

Impressão 3D de sensores flexíveis baseados em polímeros para aplicações biomédicas

Flexible self-powered sensors have great potential in the medical field, offering a means of continuous monitoring of patients, helping to prevent and diagnose diseases. The present work explores biodegradable and low-cost alternatives to produce flexible sensors, from polylactic acid, for biomedical applications. Flexible sensors are composed of 3 main parts: transducers, electrodes, and substrate. In this work, the flexible sensors object of study are constituted by an incapsulating substrate of transparent adhesive tape, electrodes produced by 3D printing of a conductive composite of polylactic acid doped with carbon black and by 2 types of transducers; poly-L-lactic (PLLA) and commercial polylactic acid (PLA) To produce the poly-L-lactic acid (PLLA) and polylactic acid (PLA) transducers, two production methods were used: solvent cast and electrospinning, corona pooling methodology was used to change its electrical state. The response of sensors to mechanical and electrical stimuli was investigated and compared. The results show that both PLA and PLLA work based on the principle of piezoelectricity and triboelectricity and respond to mechanical deformation, the best results were obtained by transducers produced by solvent casting treated by corona pooling.Sensores flexíveis autoalimentados têm grande potencial no campo da medicina, podendo oferecer meios de monotorização continua de pacientes ajudando na prevenção e diagnóstico de doenças. O presente trabalho explora alternativas biodegradáveis e de baixo custo para produção de sensores flexíveis, a partir de ácido poliláctico, destinados a aplicações biomédicas. De uma forma geral os sensores flexíveis são compostos por 3 partes principais: transdutores, elétrodos e substrato, Neste trabalho os sensores flexíveis objeto de estudo são constituídos por um substrato incapsulante de fita cola transparente, elétrodos produzidos por impressão 3D de um compósito condutor de ácido poliláctico dopado com negro de fumo e por 2 tipos de transdutores; poli-L-láctico (PLLA) e ácido poliláctico (PLA). Para produzir os transdutores de ácido poli-L-láctico (PLLA) e ácido poliláctico (PLA) foram usados dois métodos de produção: solvent cast e electrospinnig e recorreu-se à metodologia de corona pooling para alteração do seu estado elétrico. A resposta dos sensores a estímulos mecânicos e elétricos foi investigada e comparada. Os resultados mostram que tanto o PLA quanto o PLLA funcionam com base no princípio da piezoeletricidade e triboeletricidade e respondem a deformação mecânica, os melhores resultados foram obtidos pelos transdutores produzidos por solvent casting tratados por corona pooling.Mestrado em Materiais e Dispositivos Biomédico

Advanced Materials and Technologies in Nanogenerators

This reprint discusses the various applications, new materials, and evolution in the field of nanogenerators. This lays the foundation for the popularization of their broad applications in energy science, environmental protection, wearable electronics, self-powered sensors, medical science, robotics, and artificial intelligence