An actuatable ionogel thermoelectric fiber with aligned mesogens-induced unprecedented thermopower for four-dimensional dynamically adaptive heat harvesting

Thermoelectric (TE) ionogel is promising material for harvesting low-grade heat owing to their nature of quasi-solid state and giant thermopower. However, current high-performance ionogel at low humidity present multicomponent systems, resulting in a trade-off between TE property, mechanics, and cost, and their device are integrated on planar substrates, erasing their advantage of adapting to complex-shaped geometry. A TE conversion system dynamically adaptive to any curved heat surface while achieving high intrinsic TE performance remains a formidable challenge. Here, an actuated ionogel TE fiber is designed, where the fine-tuning mesogen orientations can generate unprecedented~3-fold thermopower boost (25.8 mV K-1) at low humidity via enlarging the thermal mobility difference of ion inside the liquid crystal elastomer network, accompanied by a~30-fold electrical conductivity boom. Moreover, benefiting from their actuatable and excellent mechanical properties, and internal torque inside weaving structure, a woven gripper-structured TE device achieves a four-dimensional dynamically adaptive ability to complex geometrical heat source, and thus a stable output over time regardless of changing size or temperature of the heat source. Decoupled identification of size/shape and temperature of the heat source can also be enabled. The design concepts of the actuatable TE ionogel and device pave new ways for commercial ionic thermoelectrics.