Highly-Efficient Energy Harvesting Interfaces for Implantable Biosensors

Autor:	Katic, Janko
Jazyk:	angličtina
Rok vydání:	2017
Předmět:	Energy harvesting interface thermoelectric generator glucose biofuel cell power management dc-dc converter boost converter zero-current switching zero-voltage switching implantable biosensor Energiskördsgränssnitt termoelektrisk generator glukosbiobränslecell energihantering DC-DC-omvandlare boost-omvandlare inplanterbar biosensor Other Electrical Engineering Electronic Engineering Information Engineering Annan elektroteknik och elektronik
Druh dokumentu:	Doctoral Thesis<br />Text
Popis:	Energy harvesting is identified as an alternative solution for powering implantable biosensors. It can potentially enable the development of self-powered implants if the harvested energy is properly handled. This development implies that batteries, which impose many limitations, are replaced by miniature harvesting devices. Customized interface circuits are necessary to correct for differences in the voltage and power levels provided by harvesting devices from one side, and required by biosensor circuits from another. This thesis investigates the available harvesting sources within the human body, proposes various methods and techniques for designing power-efficient interfaces, and presents two CMOS implementations of such interfaces. Based on the investigation of suitable sources, this thesis focuses on glucose biofuel cells and thermoelectric harvesters, which provide appropriate performance in terms of power density and lifetime. In order to maximize the efficiency of the power transfer, this thesis undertakes the following steps. First, it performs a detailed analysis of all potential losses within the converter. Second, in relation to the performed analysis, it proposes a design methodology that aims to minimize the sum of losses and the power consumption of the control circuit. Finally, it presents multiple design techniques to further improve the overall efficiency. The combination of the proposed methods and techniques are validated by two highly efficient energy harvesting interfaces. The first implementation, a thermoelectric energy harvesting interface, is based on a single-inductor dual-output boost converter. The measurement results show that it achieves a peak efficiency of 86.6% at 30 μW. The second implementation combines the energy from two sources, glucose biofuel cell and thermoelectric harvester, to accomplish reliable multi-source harvesting. The measurements show that it achieves a peak efficiency of 89.5% when the combined input power is 66 μW. Energiskörd har identifierats som en alternativ lösning för att driva inplanterbara biosensorer. Det kan potentiellt möjliggöra utveckling av själv-drivna inplanterbara biosensorer. Denna utveckling innebär att batterier, som sätter många begränsningar, ersätts av miniatyriserade energiskördsenheter. Anpassade gränssnittskretsar är nödvändiga för att korrigera för de skillnader i spänning och effektnivå som produceras av de energialstrande enheterna, och de som krävs av biosensorkretsarna. Denna avhandling undersöker de tillgängliga källorna för energiskörd i den mänskliga kroppen, föreslår olika metoder och tekniker för att utforma effektsnåla gränssnitt och presenterar två CMOS-implementeringar av sådana gränssnitt. Baserat på undersökningen av lämpliga energiskördskällor, fokuserar denna avhandling på glukosbiobränsleceller och termoelektriska energiskördare, som har lämpliga prestanda i termer av effektdensitet och livstid. För att maximera effektiviteten hos effektöverföringen innehåller denna avhandling följande steg. Först görs en detaljerad analys av alla potentiella förluster inom boost-omvandlare. Sedan föreslår denna avhandling en designmetodik som syftar till att maximera den totala effektiviteten och effektförbrukningen. Slutligen presenterar den flera designtekniker för att ytterligare förbättra den totala effektiviteten. Kombinationen av de föreslagna metoderna och teknikerna är varierade genom två högeffektiva lågeffekts energigränssnittskretsar. Den första inplementeringen är ett termoelektriskt energiskördsgränssnitt baserat på en induktor, med dubbla utgångsomvandlare. Mätresultaten visar att omvandlaren uppnår en maximal effektivitet av 86.6% vid 30 μW. Det andra genomförandet kombinerar energin från två källor, en glukosbiobränslecell och en termoskördare, för att åstadkomma en tillförlitlig multi-källas energiskördslösning. Mätresultaten visar att omvandlaren uppnår en maximal effektivitet av 89.5% när den kombinerade ineffekten är 66 μW. QC 20170508 Mi-SoC
Databáze:	Networked Digital Library of Theses & Dissertations
Externí odkaz:	http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-206588 Zobrazit plný text záznamu