With the miniaturization of electronic devices and the integration of flexible wearable devices, collecting energy from the surrounding environment to power low-power wearable electronics has attracted widespread attention from researchers. Natural evaporation from lakes and seas, as well as transpiration and respiration from plants, means that moisture is ubiquitous in the atmospheric environment. In recent years, researchers have deeply studied nanomaterials for collecting electrical energy from environmental moisture, such as carbon nanomaterials, biomass nanomaterials, and metal oxides, providing continuous energy for flexible wearable electronic devices.
Researcher Chaoxu Li from the Green Reaction Separation and Process Intensification Technology Center at Qingdao Energy Institute led a high-end materials manufacturing research team to address the compatibility issues between two-dimensional materials MXene and liquid metal (LM) micro/nano droplets. They proposed using natural polysaccharides (sodium alginate) as surfactants and studied the interfacial interaction mechanisms between LM and MXene, resolving the compatibility issue and constructing a coating structure of MXene/LM micro/nano droplets, achieving solvent evaporation-induced sintering of LM micro/nano droplets. The study found that the capillary action generated during evaporation of the sodium alginate-dispersed LM nanodroplets mixed with MXene’s aqueous dispersion could promote the fusion sintering of LM nanodroplets settling under gravity, thereby constructing the MXene/LM heterogeneous film. It was discovered that this film has spontaneous continuous actuation capability under a humidity gradient (driving speed of 260 °s-1, oscillation time greater than 3×104 s), with in-depth research revealing that the volume change difference of the hygroscopic materials on both sides of the film is the intrinsic mechanism for self-sustained actuation under the humidity gradient. When placed in a magnetic field of 0.5 T from a permanent magnet, its self-oscillating mechanical energy generates alternating current of up to 1360μA m-2 in an external circuit. By regulating the interfacial composite mechanisms, the constructed high-conductivity self-oscillating actuator collects energy in a humid environment and powers microelectronic devices, making it widely applicable for energy conversion and collection in humid environments. This technology effectively overcomes the current challenges of sustaining moisture-powered generation processes. It not only benefits the development of intelligent materials such as self-sustaining oscillating films but also holds promise for advancing research and development of biopolymers as energy harvesting materials. Relevant results were published in the journal Adv. Funct. Mater.
The above research was supported by funding from the National Natural Science Foundation of China (Nos. 21474125, 22075307), the Shandong “Taishan Scholar Program”, the Shandong Provincial Natural Science Foundation (Nos. ZR2020ZD33, ZR2021YQ40, ZR2020KE025), the Chinese Academy of Sciences Youth Promotion Association (No. 2022209), and the Research Innovation Fund of the Qingdao Institute of Bioenergy and Bioprocess Technology / Shandong Energy Research Institute (SEI I202143 & SEI I202131) among other projects and plans. (Text/Images by Mingjie Li, Xin Peng Che)
Figure 1. Schematic of the preparation, structure, and energy harvesting function of the self-sustaining oscillating film material driven by humidity gradient.
Original link: https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202307830.
Xinpeng Che, Ting Wang, Bailang Zhang, Zhuanzhuan Zhai, Yijun Chen, Danfeng Pei, Anle Ge, Mingjie Li* and Chaoxu Li*, Two-dimensionally nano-capsulating liquid metal for self-sintering and self-oscillating bimorph composites with persistent energy-harvest property, Adv. Funct. Mater., 2023, DOI: 10.1002/adfm.202307830
Source: Qingdao Energy Institute
