Energy Harvesting Wireless Communications: A Review of Recent Advances

This article summarizes recent contributions in the broad area of energy harvesting wireless communications. In particular, we provide the current state of the art for wireless networks composed of energy harvesting nodes, starting from the information-theoretic performance limits to transmission scheduling policies and resource allocation, medium access and networking issues. The emerging related area of energy transfer for self-sustaining energy harvesting wireless networks is considered in detail covering both energy cooperation aspects and simultaneous energy and information transfer. Various potential models with energy harvesting nodes at different network scales are reviewed as well as models for energy consumption at the nodes.Comment: To appear in the IEEE Journal of Selected Areas in Communications (Special Issue: Wireless Communications Powered by Energy Harvesting and Wireless Energy Transfer

Fully Integrated Biochip Platforms for Advanced Healthcare

Recent advances in microelectronics and biosensors are enabling developments of innovative biochips for advanced healthcare by providing fully integrated platforms for continuous monitoring of a large set of human disease biomarkers. Continuous monitoring of several human metabolites can be addressed by using fully integrated and minimally invasive devices located in the sub-cutis, typically in the peritoneal region. This extends the techniques of continuous monitoring of glucose currently being pursued with diabetic patients. However, several issues have to be considered in order to succeed in developing fully integrated and minimally invasive implantable devices. These innovative devices require a high-degree of integration, minimal invasive surgery, long-term biocompatibility, security and privacy in data transmission, high reliability, high reproducibility, high specificity, low detection limit and high sensitivity. Recent advances in the field have already proposed possible solutions for several of these issues. The aim of the present paper is to present a broad spectrum of recent results and to propose future directions of development in order to obtain fully implantable systems for the continuous monitoring of the human metabolism in advanced healthcare applications

Future of smart cardiovascular implants

Cardiovascular disease remains the leading cause of death in Western society. Recent technological advances have opened the opportunity of developing new and innovative smart stent devices that have advanced electrical properties that can improve diagnosis and even treatment of previously intractable conditions, such as central line access failure, atherosclerosis and reporting on vascular grafts for renal dialysis. Here we review the latest advances in the field of cardiovascular medical implants, providing a broad overview of the application of their use in the context of cardiovascular disease rather than an in-depth analysis of the current state of the art. We cover their powering, communication and the challenges faced in their fabrication. We focus specifically on those devices required to maintain vascular access such as ones used to treat arterial disease, a major source of heart attacks and strokes. We look forward to advances in these technologies in the future and their implementation to improve the human condition

Conjoined piezoelectric harvesters and carbon supercapacitors for powering intelligent wireless sensors

To achieve total freedom of location for intelligent wireless sensors (IWS), these need to be autonomous. To achivethis today there is a need of broadband piezoelectric energy harvesting and a long-lasting energy. The Harvester needto be able to provide sufficient amount of energy for the intelligent wireless sensor to perform its task. The energystorage needs to fulfill the requirement of a large number of charge discharge cycles and contain sufficient power forthe intelligent wireless sensor.The biggest issue with piezoelectric energy harvesting today is the bandwidth limitation. Solutions today to achievelarger bandwidth make a tradeoff where the output is decreased. The biggest issue for energy storage today is thelimitation of energy density for supercapacitors and the lack of sufficient life cycles for batteries.This thesis aims to realize piezoelectric energy harvesters with broad bandwidth and maintained power output.Moreover, for energy storage in the form of supercapacitors realize an electrode material that has a high effectivesurface area, good conductivity not dependent on a conductive agent and can be used without a binder. This thesiscover background and history of the two fields, discussion of technologies used and presents solutions for piezoelectricenergy harvesting and carbon based supercapacitor storage.A Backfolded piezoelectric harvester was made of two conjoined piezoelectric cantilevers, one placed on top of abottom cantilever. By the backfolded design this thesis show that by utilizing the extended stress distribution of thebottom cantilever a maintained power output is achieved for both output peaks. By introducing asymmetry where thetop cantilever have 80% length compared with the bottom cantilever the bandwidth was increased. An effectivebandwidth of 70 Hz with voltage output above 2,75 V for 1 g is achieved.To achieve further enhanced bandwidth a piezoelectric energy harvester with selftuning was designed. Theselftuning was achieved by a sliding mass on a beam, which is conjoined, to two piezoelectric cantilevers in abackfolded structure. By introducing length asymmetry, the effective bandwidth was enhanced to 38 Hz with a poweroutput above 15 mW, for 1 g, which is sufficient for an intelligent wireless sensor to start up and transmit data.To utilize the positive output effect from conjoined cantielvers a micro harvester was fabricated. The design wasbased on the same principle as for the backfolded, but for fabrication reasons the design was made in one plane. Theharvester contain two outer cantilevers conjoined to a backfolded middle cantilever. Due to fabrication difficulties,only a mechanical characterization of the harvester was possible. The result from the characterization looks promisingfrom a harvesting point of view, by showing a clear peak that seems to be somewhat broadband.Energy storage for an autonomous wireless intelligent sensor (IWS) needs to be able to charge and discharge duringthe lifetime of the IWS. Therefor the choice fell on supercapacitors instead of batteries. Over time the supercapacitordue to its superior amount of charge and discharge cycles, outperform a battery when energy density is compared.Increasing the energy density for supercapacitors gives the advantage to prolong the providing of power to theIWS. One such electrode material is conjoined carbon nanofibers and carbon nanotubes. The material is not dependenton conductive agents or binders. The effective surface area can be expanded through a denser structure of CNF, wheremore CNT can grow. In combination with activation, which will yield more micropores, hence an increasedcapacitance for the presented synthesized material yielded 91 F/g with an effective surface area of 131 m2.There is many challenges to power an IWS on a gasturbine. This thesis cover challenges like vibrations on cables,placement issues and the charge of a supercapacitor by harvested energy that comes in small chunks. Solutions forthese challenges are offered.The presented work in this thesis shows how the bandwidth for piezoelectric energy harvesters can be broader byasymmetric implementation of conjoined resonators. In addition, the advantages of conjoined carbon electrodematerials to be implemented as electrode material in supercapacitors. Both harvester and storage are intended to beused as energy sources for intelligent wireless sensors

On-Site and External Energy Harvesting in Underground Wireless

Energy efficiency is vital for uninterrupted long-term operation of wireless underground communication nodes in the field of decision agriculture. In this paper, energy harvesting and wireless power transfer techniques are discussed with applications in underground wireless communications (UWC). Various external wireless power transfer techniques are explored. Moreover, key energy harvesting technologies are presented that utilize available energy sources in the field such as vibration, solar, and wind. In this regard, the Electromagnetic(EM)- and Magnetic Induction(MI)-based approaches are explained. Furthermore, the vibration-based energy harvesting models are reviewed as well. These energy harvesting approaches lead to design of an efficient wireless underground communication system to power underground nodes for prolonged field operation in decision agriculture

A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks

In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs

Internet of robotic things : converging sensing/actuating, hypoconnectivity, artificial intelligence and IoT Platforms

The Internet of Things (IoT) concept is evolving rapidly and influencing newdevelopments in various application domains, such as the Internet of MobileThings (IoMT), Autonomous Internet of Things (A-IoT), Autonomous Systemof Things (ASoT), Internet of Autonomous Things (IoAT), Internetof Things Clouds (IoT-C) and the Internet of Robotic Things (IoRT) etc.that are progressing/advancing by using IoT technology. The IoT influencerepresents new development and deployment challenges in different areassuch as seamless platform integration, context based cognitive network integration,new mobile sensor/actuator network paradigms, things identification(addressing, naming in IoT) and dynamic things discoverability and manyothers. The IoRT represents new convergence challenges and their need to be addressed, in one side the programmability and the communication ofmultiple heterogeneous mobile/autonomous/robotic things for cooperating,their coordination, configuration, exchange of information, security, safetyand protection. Developments in IoT heterogeneous parallel processing/communication and dynamic systems based on parallelism and concurrencyrequire new ideas for integrating the intelligent “devices”, collaborativerobots (COBOTS), into IoT applications. Dynamic maintainability, selfhealing,self-repair of resources, changing resource state, (re-) configurationand context based IoT systems for service implementation and integrationwith IoT network service composition are of paramount importance whennew “cognitive devices” are becoming active participants in IoT applications.This chapter aims to be an overview of the IoRT concept, technologies,architectures and applications and to provide a comprehensive coverage offuture challenges, developments and applications