Design and optimization of a maglev electromagnetic–triboelectric hybrid energy converter for supplying power to intelligent sensing equipment

With the rapid development of the Internet of Things (IoT), there is a growing demand for electric energy in intelligent sensing equipment. Current smart sensors are mostly powered by lithium batteries, and it is necessary to develop a new self-powered device that can replace traditional lithium batteries. This paper designs a maglev electromagnetic–triboelectric hybrid energy converter (METHEC) containing both a triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG), which can effectively collect low-frequency vibrational energy. This paper presents a complete device design and optimization system based on theoretical calculation and simulation verification, and establishes a test platform capable of evaluating the dynamic characteristics of METHEC and thus conducts some experiments for validation. In the past, the TENG related to vertical vibration only possessed the test part, and the current was less than 1 μA, with the power still less than 1 mW even with a large triboelectric area. Additionally, there is no complete research system for devices that utilize vertical vibration. The traditional EMG has a large starting torque, a large volume and can only be applied to higher frequencies, which is not convenient for wide application, and the power rarely exceeds 100 mW. According to this study, excited by the vibrational motion at a frequency of 5.2 Hz, the open-circuit voltages of TENG and EMG are 7.5 V and 9 V, respectively; the short-circuit currents of TENG and EMG are 1.1 μA and 87.7 mA, respectively; and the maximum power density of TENG reaches 7.5 mW m−2, while the peak power of EMG reaches 789.3 mW. This paper provides a complete set of innovative exploration systems combining theory, experiment and simulation optimization, which also includes the structural optimization of TENG. METHEC does not require a large starting torque and can also be adapted to low frequencies, and can thus be adapted to more environments. Compared with traditional EMG, METHEC makes it easier to realize the miniaturization of power generation equipment, and according to this research system, other models can be studied expansively.