3D Printing

3D printing thermoelectric materials more than triples their efficiency

International research team demonstrates how changing geometry and composition maximizes power generation efficiency.

An international team of researchers claims to have significantly improved the efficiency of thermoelectric materials by altering their geometry to resemble an hourglass. Unlike previous research that solely depended on the material properties of thermoelectric substances, the researchers expect their new approach to have widespread applications in thermoelectric power generation.

The joint research team was led by professors Jae Sung Son of South Korea’s Pohang University of Science and Technology (POSTECH) and Saniya LeBlanc of George Washington University. Together, they developed a new geometry for thermoelectric materials—previously confined to cuboid shapes—through geometric design and 3D printing processes. According to the team, this new design significantly enhances power generation efficiency.

Thermoelectric materials, which are central to thermoelectric technology, are typically made from solid thermoelectric semiconductor materials. Up until now, research on thermoelectric generators has focused on improving the inherent thermoelectric material properties. However, despite improvements in this area, the efficiency of thermoelectric generators is still insufficiency for practical everyday use.


The joint research team has demonstrated that simply changing the geometry and composition of thermoelectric materials can maximize power generation efficiency. By simulating eight different geometric structures, including the traditional cuboid shape and the hourglass shape, and measuring the power generation efficiency of each, the team confirmed that the hourglass consistently outperformed others under all power generation conditions.

A schematic representation of the efficiency enhancement in thermoelectric generators. [a.] shows the eight different geometries used in the study as well as the optimization of 3D printing and heat treatment processes to create high-density dislocation defects. [b.] illustrates the thermoelectric figure-of-merit (ZT) as a function of heat treatment. [c.] shows the power generation efficiency of the eight different geometries. Dotted lines represented simulated data while points indicate actual measure efficiency. (Image: POSTECH.)

The research team also reported advancements in 3D printing processes capable of producing complex-shaped thermoelectric materials by creating high-density micro-layered defects within the material to minimize thermal conductivity and increase their thermoelectric performance index (ZT) to 2.0.

The researchers claim this is the highest value achieved for thermoelectric materials produced via 3D printing.

Based on their experiments, the team fabricated thermoelectric generators using the eight different structures and measured their efficiency, finding that the hourglass-shaped generator was approximately 3.6 times more efficient than the traditional rectangular-based generator.

“This research is the first instance where efficiency has been improved by three-dimensional geometry of the material that controlled thermal and electrical transport, instead of conventional microstructure-focused research on thermoelectric materials,” said professor Jae Sung Son. “It is expected that this approach can be universally applied to all thermoelectric materials and can also be utilized in thermoelectric cooling technologies.”

The research is published in Nature Energy.

Written by

Ian Wright

Ian is a senior editor at engineering.com, covering additive manufacturing and 3D printing, artificial intelligence, and advanced manufacturing. Ian holds bachelors and masters degrees in philosophy from McMaster University and spent six years pursuing a doctoral degree at York University before withdrawing in good standing.