3D extruded composite thermoelectric threads for flexible energy harvesting

J. Peng*, I. Witting, N. Geisendorfer, M. Wang, M. Chang, A. Jakus, C. Kenel, X. Yan, R. Shah, G. J. Snyder, M. Grayson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

52 Scopus citations


Whereas the rigid nature of standard thermoelectrics limits their use, flexible thermoelectric platforms can find much broader applications, for example, in low-power, wearable energy harvesting for internet-of-things applications. Here we realize continuous, flexible thermoelectric threads via a rapid extrusion of 3D-printable composite inks (Bi2Te3n- or p-type micrograins within a non-conducting polymer as a binder) followed by compression through a roller-pair, and we demonstrate their applications in flexible, low-power energy harvesting. The thermoelectric power factors of these threads are enhanced up to 7 orders-of-magnitude after lateral compression, principally due to improved conductivity resulting from reduced void volume fraction and partial alignment of thermoelectric micrograins. This dependence is quantified using a conductivity/Seebeck vise for pressure-controlled studies. The resulting grain-to-grain conductivity is well explained with a modified percolation theory to model a pressure-dependent conductivity. Flexible thermoelectric modules are demonstrated to utilize thermal gradients either parallel or transverse to the thread direction.

Original languageEnglish (US)
Article number5590
JournalNature communications
Issue number1
StatePublished - Dec 1 2019

ASJC Scopus subject areas

  • General Physics and Astronomy
  • General Chemistry
  • General Biochemistry, Genetics and Molecular Biology


Dive into the research topics of '3D extruded composite thermoelectric threads for flexible energy harvesting'. Together they form a unique fingerprint.

Cite this