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

Environmental Energy Harvesting Techniques to Power Standalone IoT-Equipped Sensor and Its Application in 5G Communication

In the recent few years, due to its significant deployment to meet global demand for smart cities, the Internet of Things (IoT) has gained a lot of attention. Environment energy harvesting devices, which use ambient energy to generate electricity, could be a viable option in near future for charging or powering stand-alone IoT sensors and electronic devices. The key advantages of such energy harvesting gadgets are that they are environmentally friendly, portable, wireless, cost-effective, and compact. It is significant to propos and fabricate an improved, high-quality, economical, and efficient energy harvesting systems to overcome power supply to tiny IoT devices at the remote locations. In this article, various types of mechanisms for harvesting renewable energies that can power sensor enabled IoT locally, as well as its associated wireless sensor networks (WSNs), are reviewed. These methods are discussed in terms of their advantages and applications, as well as their drawbacks and limitations. Furthermore, methodological performance analysis for the decade 2005 to 2020 is surveyed in order to identify the methods that delivered high output power for each device. Furthermore, the outstanding breakthrough performances of each of the aforementioned micro-power generators during this time period are emphasized. According to the research, thermoelectric modules can convert up to 2500×10^(-3) W/cm^2, thermo-photovoltaic 10.9%, piezoelectric 10,000 mW/cm^3 and microbial fuel cell 6.86 W/m^2 of energy. Doi: 10.28991/esj-2021-SP1-08 Full Text: PD

A multiscale-multiphysics strategy for numerical modeling of thin piezoelectric sheets

Flexible piezoelectric devices made of polymeric materials are widely used for micro- and nano-electro-mechanical systems. In particular, numerous recent applications concern energy harvesting. Due to the importance of computational modeling to understand the influence that microscale geometry and constitutive variables exert on the macroscopic behavior, a numerical approach is developed here for multiscale and multiphysics modeling of piezoelectric materials made of aligned arrays of polymeric nanofibers. At the microscale, the representative volume element consists in piezoelectric polymeric nanofibers, assumed to feature a linear piezoelastic constitutive behavior and subjected to electromechanical contact constraints using the penalty method. To avoid the drawbacks associated with the non-smooth discretization of the master surface, a contact smoothing approach based on B\'ezier patches is extended to the multiphysics framework providing an improved continuity of the parameterization. The contact element contributions to the virtual work equations are included through suitable electric, mechanical and coupling potentials. From the solution of the micro-scale boundary value problem, a suitable scale transition procedure leads to the formulation of a macroscopic thin piezoelectric shell element.Comment: 11 pages, 6 pages, 21 reference

Piezoelectric energy harvesting from traffic-induced pavement vibrations

This paper focuses on the development and experimental testing of a potential clean energy source for powering the remote equipment used in transportation infrastructure. Traditional power sources (i.e., power cables and batteries) are excessively expensive or infeasible in this type of application. A compression-based roadway energy harvester has been developed that can be embedded into pavement to scavenge electrical energy from traffic-induced vibrations. The proposed roadway harvester employs a group of piezoelectric harvesting units to convert traffic-induced vibrations into electrical energy, and each single harvesting unit contains three piezoelectric multilayer stacks. According to the linear theory of piezoelasticity, a two-degree-of-freedom electromechanical model of the piezoelectric harvesting unit was developed to characterize its performance in generating electrical energy under external excitations. Experimental testing in the laboratory was conducted to investigate the output power properties of the harvesting unit and shows good agreement with the theoretical analysis. Based on the testing results of the harvesting unit, the capability of the proposed roadway harvester has been theoretically evaluated and demonstrated that it has the ability to generate sufficient energy for driving common electrical equipment used in transportation infrastructure. © 2014 AIP Publishing LLC

Piezoelectric wind power harnessing – an overview

As fossil energy resources deplete, wind energy gains ever more importance. Recently, piezoelectric energy harvesting methods are emerging with the advancements in piezoelectric materials and its storage elements. Piezoelectric materials can be utilized to convert kinetic energy to electrical energy. Utilization of piezoelectric wind harvesting is a rather new means to convert renewable wind energy to electricity. Piezoelectric generators are typically low cost and easy to maintain. This work illustrates an overview of piezoelectric wind harvesting technology. In wind harvesting, piezoelectric material choice is of the first order of importance. Due to their strain rate, robustness is a concern. For optimum energy harvesting efficiency resonant frequency of the selected materials and overall system configuration plays important role. In this work, existing piezoelectric wind generators are grouped and presented in following categories: leaf type, rotary type, rotary to linear type and beam type wind generators

Design and experimentation of a solar power system powering measurement chains in concrete structures strengthened with fiber-reinforced polymer rebars

Aquest treball de fi de grau té com a objectiu explorar la viabilitat d'utilitzar plaques solars per alimentar cadenes de mesura en estructures de formigó enfortides amb barres de polímer reforçat amb fibra (FRP). Els principals objectius són: dur a terme una investigació profunda per entendre el funcionament de cada element que conforma el sistema, valorar diverses alternatives, identificar aspectes a tenir en compte respecte a la configuració del model, dissenyar un sistema d'energia solar a mida i realitzar-hi proves experimentals. L'experiment implica una prova de flexió de 3 punts, on la barra de FRP s’ha sotmès a diferents condicions de càrrega. La mesura de la tensió ha sigut l'objectiu principal, tenint en compte la seva sensibilitat a la temperatura, factors ambientals i variacions de càrrega. La prova revela diferències entre la suspensió de càrrega directa i les suspensions seqüencials, destacant l'impacte de la magnitud de la càrrega, la distribució i la resposta estructural en els valors de deformació. Els resultats han demostrat l'eficàcia dels panells solars per proporcionar energia sostenible per a les cadenes de mesura. L'anàlisi d'alternatives mostra el potencial de l'energia solar en aquests tipus de muntatges i com a conseqüència la possible contribució al desenvolupament sostenible dels sistemes de mesura en el sector de la construccióEste trabajo de fin de grado tiene como objetivo explorar la viabilidad de utilizar placas solares para alimentar cadenas de medida en estructuras de hormigón fortalecidas con barras de polímero reforzado con fibra (FRP). Los principales objetivos son: llevar a cabo una investigación profunda para entender el funcionamiento de cada elemento que conforma el sistema, valorar diversas alternativas, identificar aspectos a tener en cuenta respecto a la configuración del modelo, diseñar un sistema de energía solar a medida y realizar pruebas experimentales. El experimento implica una prueba de flexión de 3 puntos, donde la barra de FRP se ha sometido a distintas condiciones de carga. La medida de la tensión ha sido el principal objetivo, teniendo en cuenta su sensibilidad a la temperatura, factores ambientales y variaciones de carga. La prueba revela diferencias entre una suspensión de carga directa y suspensiones secuenciales, destacando el impacto de la magnitud de la carga, distribución y respuesta estructural en los valores de deformación. Los resultados han demostrado la eficacia de los paneles solares para proporcionar energía sostenible a las cadenas de medida. El análisis de alternativas muestra el potencial de la energía solar en este tipo de montajes y como consecuencia de la posible contribución al desarrollo sostenible de los sistemas de medida en el sector de la construcciónThis final project aims to explore the viability of using solar panels for powering measurement chains in concrete structures reinforced with fiber-reinforced polymer bars (FRP). The main objectives of the thesis are to carry out in-depth research to understand the operation of each element that makes up the system, assess various alternatives, identify aspects to take into account regarding the configuration of the model, design a custom solar energy system and carry out experimental tests. The experiment involves a 3-point bending test, where the FRP rebar has been subjected to different load conditions. The strain measurement has been the primary focus, considering its sensitivity to temperature, environmental factors, and load variations. The test reveals differences between a direct load suspension and sequential suspensions, highlighting the impact of load magnitude, distribution, and structural response on strain values. The results have demonstrated the effectiveness of solar panels in providing sustainable energy for measurement chains. The analysis of alternatives shows the potential of solar energy in this type of set ups and therefore the possible contribution to the sustainable development of measurement systems in the construction secto

Power Approaches for Implantable Medical Devices.

Implantable medical devices have been implemented to provide treatment and to assess in vivo physiological information in humans as well as animal models for medical diagnosis and prognosis, therapeutic applications and biological science studies. The advances of micro/nanotechnology dovetailed with novel biomaterials have further enhanced biocompatibility, sensitivity, longevity and reliability in newly-emerged low-cost and compact devices. Close-loop systems with both sensing and treatment functions have also been developed to provide point-of-care and personalized medicine. Nevertheless, one of the remaining challenges is whether power can be supplied sufficiently and continuously for the operation of the entire system. This issue is becoming more and more critical to the increasing need of power for wireless communication in implanted devices towards the future healthcare infrastructure, namely mobile health (m-Health). In this review paper, methodologies to transfer and harvest energy in implantable medical devices are introduced and discussed to highlight the uses and significances of various potential power sources

Investigation of electrical properties for cantilever-based piezoelectric energy harvester

In the present era, the renewable sources of energy, e.g., piezoelectric materials are in great demand. They play a vital role in the field of micro-electromechanical systems, e.g., sensors and actuators. The cantilever-based piezoelectric energy harvesters are very popular because of their high performance and utilization. In this research-work, an energy harvester model based on a cantilever beam with bimorph PZT-5A, having a substrate layer of structural steel, was presented. The proposed energy scavenging system, designed in COMSOL Multiphysics, was applied to analyze the electrical output as a function of excitation frequencies, load resistances and accelerations. Analytical modeling was employed to measure the output voltage and power under pre-defined conditions of acceleration and load resistance. Experimentation was also performed to determine the relationship between independent and output parameters. Energy harvester is capable of producing the maximum power of 1.16 mW at a resonant frequency of 71 Hz under 1g acceleration, having load resistance of 12 k Omega. It was observed that acceleration and output power are directly proportional to each other. Moreover, the investigation conveys that the experimental results are in good agreement with the numerical results. The maximum error obtained between the experimental and numerical investigation was found to equal 4.3%

Energy harvesting and wireless transfer in sensor network applications: Concepts and experiences

Advances in micro-electronics and miniaturized mechanical systems are redefining the scope and extent of the energy constraints found in battery-operated wireless sensor networks (WSNs). On one hand, ambient energy harvesting may prolong the systems lifetime or possibly enable perpetual operation. On the other hand, wireless energy transfer allows systems to decouple the energy sources from the sensing locations, enabling deployments previously unfeasible. As a result of applying these technologies to WSNs, the assumption of a finite energy budget is replaced with that of potentially infinite, yet intermittent, energy supply, profoundly impacting the design, implementation, and operation of WSNs. This article discusses these aspects by surveying paradigmatic examples of existing solutions in both fields and by reporting on real-world experiences found in the literature. The discussion is instrumental in providing a foundation for selecting the most appropriate energy harvesting or wireless transfer technology based on the application at hand. We conclude by outlining research directions originating from the fundamental change of perspective that energy harvesting and wireless transfer bring about

A Three – tier bio-implantable sensor monitoring and communications platform

One major hindrance to the advent of novel bio-implantable sensor technologies is the need for a reliable power source and data communications platform capable of continuously, remotely, and wirelessly monitoring deeply implantable biomedical devices. This research proposes the feasibility and potential of combining well established, ‘human-friendly' inductive and ultrasonic technologies to produce a proof-of-concept, generic, multi-tier power transfer and data communication platform suitable for low-power, periodically-activated implantable analogue bio-sensors. In the inductive sub-system presented, 5 W of power is transferred across a 10 mm gap between a single pair of 39 mm (primary) and 33 mm (secondary) circular printed spiral coils (PSCs). These are printed using an 8000 dpi resolution photoplotter and fabricated on PCB by wet-etching, to the maximum permissible density. Our ultrasonic sub-system, consisting of a single pair of Pz21 (transmitter) and Pz26 (receiver) piezoelectric PZT ceramic discs driven by low-frequency, radial/planar excitation (-31 mode), without acoustic matching layers, is also reported here for the first time. The discs are characterised by propagation tank test and directly driven by the inductively coupled power to deliver 29 μW to a receiver (implant) employing a low voltage start-up IC positioned 70 mm deep within a homogeneous liquid phantom. No batteries are used. The deep implant is thus intermittently powered every 800 ms to charge a capacitor which enables its microcontroller, operating with a 500 kHz clock, to transmit a single nibble (4 bits) of digitized sensed data over a period of ~18 ms from deep within the phantom, to the outside world. A power transfer efficiency of 83% using our prototype CMOS logic-gate IC driver is reported for the inductively coupled part of the system. Overall prototype system power consumption is 2.3 W with a total power transfer efficiency of 1% achieved across the tiers