Recently, Prof. Zhang Min and Huang Youchao published their research results entitled ” A Mechanically Tunable Electromagnetic Wave Harvester and Dual-modal Detector based on Quasi-static van der Waals Heterojunction” on Nano Energy (the SCI of zone 1 with IF =17.881) as the corresponding author and the first author respectively.
By applying pressure to van der Waals contact heterojunction, a mechanically adjustable electromagnetic energy collecting device is proposed and realized, which provides a new perspective for the study of energy conversion mechanism of friction volt DC generator based on van der Waals contact heterojunction. In this work, it is proposed for the first time that the device structure of the frictional volt-DC generator based on van der Waals contact heterojunction is similar to that of the single heterojunction rectifier antenna, so the frictional volt-DC generator can absorb electromagnetic energy in the environment under quasi-static conditions. Since the electrical characteristics of the heterojunction are regulated by pressure, van der Waals contact heterojunction can be used as an electromagnetic energy collector to achieve the switching state under the control of external pressure. The design and mechanism proposed by this work are universal and have been validated in devices fabricated from different materials and structures. The electromagnetic energy collector can directly charge capacitors, light up leds, power low-power inverters, and act as a dual-mode sensor to detect external electromagnetic radiation and pressure in real time. The mechanically adjustable electromagnetic energy collector proposed in this study has potential applications in wearable electronic devices, intelligent robots and the Internet of things.
Electromagnetic (EM) wave harvesting and detection have many implications for self-powered human health monitoring and robot intelligence. Heterojunction-based energy harvesters and detectors can convert various forms of energy into electricity. Here, we report a mechanically tunable electromagnetic wave harvester (EMH), operated by quasi-static contact of a metal/indium gallium zinc oxide/metal van der Waals heterojunction. The proposed EMH behaves as a rectenna responding to low-frequency signals (80–400 MHz), where the electrode works as an antenna, the heterojunction between two separated layers works as a rectifying diode, and the parallel structure works as a capacitor. It is found that the pressure on the EMH plays an important role on regulating electronic interfaces and thus the output characteristics. The two output states (on/off states) of the EMH can be reversibly controlled by mechanical pressure. The proposed design and mechanism have been verified by various materials pairings and structures, which proves their great universality. The simple-structure EMH can continuously generate DC power for 10 hours without signal attenuation. It can supply power to a capacitor, a LED and a resistive load inverter, which demonstrates its application potential as an energy source. Moreover, the EMH can work as a sensor to qualitatively detect electromagnetic waves in the ambient environment and pressure. This work has proposed a novel solution to harvest and detect electromagnetic energy by van der Waals heterojunction in a mechanically controllable way, providing new possibilities for wearable electronics, intelligent robots, and Internet of Things.
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