Wearable and flexible Bi2Te3/PEDOT:PSS coated thermoelectric aramid yarn for harvesting body heat

Flexible thermoelectric yarn based on inorganic particles and polymer layer • The Seebeck coefficient and power factor reached 127 μV K −1 and 34 μW m −1  K −2 • Continuous transferring heat into electricity in the vertical direction • TE device able to generate 10 μW m −2 when temperature difference is 8 K. Yarn based wearable thermoelectric (TE) generator which can transfer body heat into electricity, shows a potential application in driving flexible electronic devices. Although there are many TE materials that have been loaded on aramid yarn, achieving flexible 5inorganic material-based TE yarn is still a challenge. Here, a bismuth telluride (Bi 2 Te 3 ) and PEDOT:PSS (BTP) coated aramid yarn is fabricated by solution thermal and dip coating method. The thermoelectric properties can be improved by increasing reaction times. The highest Seebeck coefficient and power factor of BTP yarn reach up to 127 μV K −1 and 34 μW m −1  K −2 , respectively. The BTP yarn also shows good mechanical property and flexibility. By utilizing finite element analysis, the temperature distribution under different weather is simulated. According to the simulated result, strategies to enhance the output performance of TE device in different weather are proposed, including changing fabric color and thickness. For the application, four TE yarn units are connected in series and then embroidered into fabric. The TE device can output 10 μW m −2 when temperature difference is 8 K. This exploratory work of combining inorganic and organic TE material with the aramid yarn provides a new way to achieve high performance TE yarn. Download: Download high-res image (68KB) Download: Download full-size image