Jaeyoung Jang1
Hanyang University1
Thermoelectric (TE) technology has a large potential market and wide-ranging applications, from powering of electronic devices to automotive/industrial waste heat cogeneration.[1,2] Especially, TE energy harvesters are expected to be combined with soft, wearable, mobile, wireless smart devices that can constitute tomorrow’s Internet of Things.[1] In certain types of such applications, TE materials are required to be robust to and stable under external damage and severe mechanical stresses, achieving which using commercialized inorganic materials may be difficult. In the recent decade, development of organic TE materials has gained significant attention given their advantages over their inorganic counterparts, e.g., low thermal conductivity, low weight, natural abundance, environmental friendliness, and mechanical flexibility.[3,4,5] However, organic TE materials that are both self-healable and stretchable have not yet been demonstrated. Also, patch-type soft TE materials, which can directly utilize waste heats from practical heat sources including human body without any additional support, have not been developed yet.<br/>To meet these mechanical criteria, a strategy is reported in the first part of this presentation, employing a thermoplastic elastomer as the matrix of a ternary blend system in which p-doped polymer nanowires are electrically percolated to impart TE properties.[6] The resulting organic TE composites exhibit excellent self-healing and stretching properties under external damage and mechanical stresses.[6] In the last part of this presentation, realization of highly surface-conformable TE patches based on human friendly hydro-gels will be discussed.[7] The patches are repeatedly applicable to various types of heat sources with different surface features and material textures, not only harvesting thermal energy from the heat source but also precisely sensing the temperatures because they form excellent thermal contacts with arbitrary substrates.[7] These proof-of-concept studies will be of great significance for developing self-healable, stretchable, and body-attachable TE energy harvesters and temperature sensors for use in next-generation electronics including e-skins and wearable soft devices.<br/><br/>[1] C. Bounioux, … C. Müller <i>Energy Environ. Sci.</i> <b>2013</b>, <i>6</i>, 918-925.<br/>[2] R. Kroon, … C. Müller <i>Chem</i>. <i>Soc</i>. <i>Rev</i>. <b>2016</b>, <i>45</i>, 6147-6164.<br/>[3] E. H. Suh, … J. Jang <i>Adv. Energy Mater.</i> <b>2020</b>, <i>10</i>, 2002521.<br/>[4] E. H. Suh, … J. Jang <i>Nano</i> <i>Energy</i> <b>2019</b>, <i>58</i>, 585-595.<br/>[5] J. Jung, … J. Jang <i>ACS</i> <i>Appl. Mater. Interfaces</i> <b>2019</b>, <i>11</i>, 47330-47339.<br/>[6] Y. J. Jeong, … J. Jang <i>Adv. Funct</i>.<i> Mater.</i> <b>2020</b>, <i>30</i>, 1905809.<br/>[7] T. S. Lee, … J. Jang <i>in preparation.</i>