Monolithic Carbon Nanotube Film Thermoelectric Generator

The design and development of a thermoelectric generator (TEG) with minimal internal resistance is crucial for achieving high output power in self-powered wearable technologies. This work presents a novel flexible TEG comprising single-walled carbon nanotube (SWCNT) thermoelements, fabricated through a sacrificial molding process. Different from the traditional TEG structural design, our TEG’s
${p}$
- and
${n}$
-type SWCNT thermoelements are formed monolithically without any interconnections. This integration eliminates the presence of internal resistance within the device. Equipped with eight pairs of the
${p}$
- and
${n}$
-type SWCNT thermoelements, the TEG exhibits an open-circuit voltage (
${V}_{\text {oc}}{)}$
of ~21.82 mV and an internal resistance of
$\sim 16.56~\Omega $
, corresponding to a maximum output power of approximately
$7.19~\mu \text{W}$
at a temperature gradient
$(\Delta {T})$
of 50 °C. Additionally, the TEG demonstrated its capability to harvest energy from a fingertip, generating a
${V}_{\text {oc}}$
of around 2.58 mV at a
$\Delta {T}$
of 8.8 °C. These results highlight the potential of the monolithically formed SWCNT thermoelements for achieving high-power density TEGs.