Rapid technological advancements have reduced the size and increased the portability of electronics. In 2021, the number of portable devices reached 12.2 billion globally, and is predicted to exceed 25 billion in 2025. Such an immense number of small electronics has resulted in an ever-increasing demand for energy. However, existing energy sources are primarily derived from unsustainable resources such as coal, oil and natural gas, which are non-renewable and cause pollution. Therefore, developing renewable and sustainable types of energy is an important, urgent, albeit challenging task. Prof. Xu Bingang’s research focuses on an important direction: determining how to provide a green, renewable and sustainable power supply for wearable electronic devices. To tackle this issue, his team has carried out avant-garde research on utilising human motions like walking and running, and environmental sources like sunlight, heat and humidity, to convert mechanical, solar, thermal and humidity energy into usable electric energy for sustainable applications. The works are based on the individual energy-conversion effects of piezoelectric, triboelectric, photoelectric, thermoelectric, and moist-electric effects. To further enlarge the input energy capacity for higher performance, his team has also made effort to combine or integrate these energy-conversion effects by developing a kind of hybrid energy harvester that is able to harvest renewable energies from multiple sources simultaneously (like mechanical, solar, moisture and thermal energy) and then convert them into electricity. The main challenges for developing this kind of hybrid energy harvesting method lies in the fundamental study and novel designs of functional materials that can effectively resolve the problem of synergistic coupling and fusion of different input energies into a single device unit.
More recently, Prof. Xu’s team has made an innovative breakthrough in the field by fundamentally disclosing and designing a new type of hybrid multi-energy harvesting strategy. This development is based on their new understanding and synergistical regulation of charge generation and transfer dynamics by integrating ferroelectric and photovoltaic effects with the tribovoltaic effect. With this new strategy, the developed multi-energy devices are flexible for wearing and can also deliver an impressive direct current (DC) electric output of 7.3 V and 69.8 µA, thus outperforming those in other reported works. In addition to driving portable devices, the flexible multi-energy harvesting device is also capable of self-powered multifunctional sensing, including sensing temperature, humidity, bending, and photodetection. This study proposes new scientific insights into modulating the electric performance of hybrid energy harvesting while extending its functionality to applications in smart wearables and e-textiles.
This work is published in Advanced Energy Materials (https://onlinelibrary.wiley.com/doi/10.1002/aenm.202402145), a top-tier journal in Materials Science with an impact factor of 24.4. The first two authors are respectively Drs Xin Yin and Yujue Yang, a postdoctoral fellow and a new PhD graduate (2024) under the supervision of Prof. Xu.
