Master's lecture in Environment and Natural Resources - Christopher Aleman
VR-II
Stofa 258
Master's student: Christopher Aleman
Title: Harvesting energy from carbon nanotube candles
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Faculty: Faculty of Physical Sciences
Advisors: Einar Örn Sveinbjörnsson and Snorri Þorgeir Ingvason, both Professors at the Faculty of Physical Sciences
Examiner: Halldór Guðfinnur Svavarsson, Associate Professor at Reykjavik University
Abstract
Carbon nanotubes possess extraordinary properties and were only introduced to the world around three decades ago. New applications and models of CNTs continue to surface both in the micro and macroscopic world. CNTs’ high thermal and electric conductivity properties suit them well for thermoelectric energy harvesting materials. The Seebeck Effect in particular, is the phenomena of thermoelectric energy harvesting, which entails a flow of electrical current caused by the temperature difference between two conductors in contact with each other. By forming a junction between an average 5 μm diameter CNT thread and 25 μm diameter platinum line, we were able to produce a thermoelectric energy harvesting system in the fashion of a liquid fuel candle. The tea-sized candle consisted of a CNT thread acting as the wick, where majority of the thread was submerged in liquid fuel. The exposed portion of the CNT was connected orthogonally to a platinum line and their junction was the point of ignition. With the aid of a microcapillary tube, liquid fuel traveled vertically up the CNT to provide a stable flow of fuel. Our thermoelectric candle produced maximum power of 30 1nW but when doubling the amount of CNT and platinum the candles power increased to 963nW . The voltage was dependent on both the material amount and flame relation to the junction but remained constant for a long duration. Longer duration tests were administered to monitor the circuit’s voltage over time. Maximizing an output voltage to a more efficient degree maybe possible by quantizing the capillary force of CNTs in order to better supply the ideal amount of fuel for the desired flame size. These results demonstrate candles can produce harvestable energy, even though there might not be an current use or storage procedure for the limited amount of energy harvested from a single candle.