2022 Fiscal Year Annual Research Report
Creation of thermofluidic energy harvesting elements to surpass the solid-state thermoelectric energy conversion
| Project/Area Number |
21K18693
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| Research Institution | Kyushu University |
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Principal Investigator |
李 秦宜 九州大学, 工学研究院, 准教授 (60792041)
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| Co-Investigator(Kenkyū-buntansha) |
高橋 厚史 九州大学, 工学研究院, 教授 (10243924)
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| Project Period (FY) |
2021-07-09 – 2023-03-31
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| Keywords | 発電素子 / ナノチャネル / グラフェン / カーボンナノチューブ |
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| Outline of Annual Research Achievements |
This project aims to experimentally elucidate the complex interfacial electrification phenomena involving flow, electric and thermal effects, and to create energy harvesting elements based on nanofluidics. In FY2022, following the slip flow measurement method that we developed in the previous year, we first systematically studied the slip flow in graphene nanochannels changing with surface electric charging. We found that the slip length of water and salt solutions on graphene decreases with increasing surface charge density, which can be well explained by recently developed theories. Second, we studied the electric potential generated across the graphene nanochannel due to flow and evaporation. A voltage of several millivolts was generated from the spontaneous capillary flow of pure water in the graphene nanochannels. We elucidated how the liquid flow and evaporation rates contribute to electricity generation at various confinements and temperatures. Third, we successfully filled various salt solutions into individual carbon nanotubes, which are ready for in-depth investigation of interfacial electrification effects. In summary, during this project, we have developed an accurate method for the flow measurement in nanochannels with depths of tens to hundreds of nanometers, elucidated the reciprocal relations between the capillary filling and surface charge in graphene-coated nanochannels, and established efficient methods to fill various liquids into individual carbon nanotubes.
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