Energy generation from vast amount low-grade heat sources (below 100 ℃, e.g. waste water, metal smelting) is alternative way to ease the energy crisis. Generally, the applied semiconductor thermoelectric materials and thermo-electrochemical devices for heat harvesting purpose are difficult to realize large-scale and efficient conversion, as well as the ability of anti-potential corrosion and depletion by electrolytes.
Prof. Liping Wen’s group at Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences is inspired by the human skin and successfully developed an ionic nanochannel to transform heat into electricity. Similar to the thermo-TRP in the skin, asymmetric polyimide nanochannel by track-etching technique was covered with negative carboxylates. The obtained power density can reach 88.8 Wm-2 with a temperature gradient of 40 ℃ by simply direct ion flow through the nanochannel. The thermoelectric conversion system provides a new way to harvest clean energy, also the electronic skin field and skin prosthetics.
Figure. An prototype of the BSN‐based LGH energy harvester. A,B) Schematic composition and the photograph of the flexible harvester. C) Generated power of the flexible energy harvester as a function of temperature gradient. D) Correlation between temperature gradient and action current. (Image by Ganhua Xie)
The study entitled “Skin-Inspired Low-Grade Heat Energy Harvesting Using Directed Ionic Flow through Conical Nanochannels” has been published in Advanced Energy Materials.