Milliwatt-scale 3D thermoelectric generators via additive screen printing.

Area of Science:

• Materials Science
• Energy Harvesting
• Sustainable Electronics

Background:

• Digitalization relies on electronic components like wearables and IoT devices, increasing energy demand.
• Lithium-ion batteries are the primary power source, raising sustainability concerns.
• Thermoelectric generators (TEGs) offer a potential battery alternative for low-power applications.

Purpose of the Study:

• To explore cost-effective, fully printed thermoelectric generators (TEGs) as a sustainable power source.
• To overcome limitations of high contact resistance and thickness in printed TEGs.

Main Methods:

• Developed an additive screen-printing method for fabricating two types of 3D printed TEGs (print-TEG I and print-TEG II).
• Utilized layer-by-layer printing of electrodes, interlayers, and n-type (Ag2Se) and p-type (Bi0.5Sb1.5Te3) legs.
• Investigated six different layout configurations for the printed TEGs.

Main Results:

• Achieved a fill factor of 0.36, addressing contact resistance and thickness challenges.
• The print-TEG II with 50 thermocouples generated a maximum power output (Pmax) of 1.22 mW and an open-circuit voltage (VOC) of 268 mV at ΔT = 43 K.
• Demonstrated a highest power density (Pd) of 67 μW cm−2 (>400 μW g−1) for a fully printed planar TEG.

Conclusions:

• The developed screen-printing method enables cost-effective fabrication of high-performance printed TEGs.
• Printed TEGs show significant potential as a reliable, non-stop power source for low-power electronic devices.
• This technology offers a sustainable alternative to batteries in the growing market for digital electronics.