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Title: Development of thermoelectric fibers for miniature thermoelectric devices

Abstract

Miniature thermoelectric (TE) devices may be used in a variety of applications such as power sources of small sensors, temperature regulation of precision electronics, etc. Reducing the size of TE elements may also enable design of novel devices with unique form factor and higher device efficiency. Current industrial practice of fabricating TE devices usually involves mechanical removal processes that not only lead to material loss but also limit the geometry of the TE elements. In this project, we explored a powder-processing method for the fabrication of TE fibers with large length-to-area ratio, which could be potentially used for miniature TE devices. Powders were milled from Bi2Te3-based bulk materials and then mixed with a thermoplastic resin dissolved in an organic solvent. Through an extrusion process, flexible, continuous fibers with sub-millimeter diameters were formed. The polymer phase was then removed by sintering. Sintered fibers exhibited similar Seebeck coefficients to the bulk materials. Moreover, their electrical resistivity was much higher, which might be related to the residual porosity and grain boundary contamination. Prototype miniature uni-couples fabricated from these fibers showed a linear I-V behavior and could generate millivolt voltages and output power in the nano-watt range. Further development of these TE fibers requiresmore » improvement in their electrical conductivities, which needs a better understanding of the causes that lead to the low conductivity in the sintered fibers.« less

Authors:
 [1];  [2];  [2];  [2]
  1. Temple Univ., Philadelphia, PA (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1287025
Grant/Contract Number:
AC05-00OR22725
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Electronic Materials
Additional Journal Information:
Journal Volume: 45; Journal Issue: 3; Journal ID: ISSN 0361-5235
Publisher:
Springer
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; thermoelectrics; powder processing; fiber; power generator; composite

Citation Formats

Ren, Fei, Menchhofer, Paul A., Kiggans, Jr., James O., and Wang, Hsin. Development of thermoelectric fibers for miniature thermoelectric devices. United States: N. p., 2016. Web. doi:10.1007/s11664-015-4050-8.
Ren, Fei, Menchhofer, Paul A., Kiggans, Jr., James O., & Wang, Hsin. Development of thermoelectric fibers for miniature thermoelectric devices. United States. doi:10.1007/s11664-015-4050-8.
Ren, Fei, Menchhofer, Paul A., Kiggans, Jr., James O., and Wang, Hsin. 2016. "Development of thermoelectric fibers for miniature thermoelectric devices". United States. doi:10.1007/s11664-015-4050-8. https://www.osti.gov/servlets/purl/1287025.
@article{osti_1287025,
title = {Development of thermoelectric fibers for miniature thermoelectric devices},
author = {Ren, Fei and Menchhofer, Paul A. and Kiggans, Jr., James O. and Wang, Hsin},
abstractNote = {Miniature thermoelectric (TE) devices may be used in a variety of applications such as power sources of small sensors, temperature regulation of precision electronics, etc. Reducing the size of TE elements may also enable design of novel devices with unique form factor and higher device efficiency. Current industrial practice of fabricating TE devices usually involves mechanical removal processes that not only lead to material loss but also limit the geometry of the TE elements. In this project, we explored a powder-processing method for the fabrication of TE fibers with large length-to-area ratio, which could be potentially used for miniature TE devices. Powders were milled from Bi2Te3-based bulk materials and then mixed with a thermoplastic resin dissolved in an organic solvent. Through an extrusion process, flexible, continuous fibers with sub-millimeter diameters were formed. The polymer phase was then removed by sintering. Sintered fibers exhibited similar Seebeck coefficients to the bulk materials. Moreover, their electrical resistivity was much higher, which might be related to the residual porosity and grain boundary contamination. Prototype miniature uni-couples fabricated from these fibers showed a linear I-V behavior and could generate millivolt voltages and output power in the nano-watt range. Further development of these TE fibers requires improvement in their electrical conductivities, which needs a better understanding of the causes that lead to the low conductivity in the sintered fibers.},
doi = {10.1007/s11664-015-4050-8},
journal = {Journal of Electronic Materials},
number = 3,
volume = 45,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
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  • The authors have designed and built a single-crystal fiber growth apparatus. The apparatus employs novel optical, mechanical, and electronic control systems that enable the growth of high optical quality single-crystal fibers. The authors have grown oriented single-crystal fibers of four refractory oxide materials, Al/sub 2/O/sub 3/, Cr:Al/sub 2/O/sub 3/, Nd:YAG, and LiNbO/sub 3/. These materials exhibit similar growth characteristics and yield fibers of comparable quality. Fibers as small as 20 ..mu..m in diameter and as long as 20 cm have been grown. Measured optical losses at 1.06 ..mu..m for a 10-cm-long, 170-..mu..m-diam Cr:Al/sub 2/O/sub 3/ fiber were 0.074 dB/cm. 28more » references, 9 figures, 1 table.« less
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  • Abstract not provided.
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