Miniaturized springless hybrid nanogenerator for powering portable and wearable electronic devices from human-body-induced vibration

In this paper, a springless hybridized NG (nanogenerator) was newly designed to have a non-resonant behavior, in which the output power continuously increases with the input frequency and amplitude. To achieve a considerably higher output power generation at low-frequency vibrations and low amplitude, the proposed springless hybrid electromagnetic and triboelectric nanogenerator (SHEMG-TENG) utilizes a dual-Halbach array, which is fabricated with contact-separation and sliding-mode TENGs. The proposed SHEMG-TENG is fabricated and verified from a vibration exciter and human-body-induced vibration. Under the vibration exciter test (horizontal position), the fabricated SHEMG-TENG generated an output current and power of 2.04 mA and 5.41 mW, respectively, which corresponds to a volume power density of 395.4 W/m³ under a matching load resistance of 1.1 KΩ at an applied frequency and acceleration of 6 Hz and 1 g, respectively. For a number of basic human activities such as handshaking, walking, and slow running, the SHEMG-TENG was able to deliver output powers are 2.9 mW, 1.2 mW, and 1.7 mW (horizontal position), respectively, and 1.6 mW, 0.74 mW, and 2.3 mW (vertical position), respectively. This work presents an important step toward realizing SHEMG-TENG from human-body-induced vibration powered to enable wearable and portable smart electronic applications, and is expected to be widely accepted by the general public in their daily lifestyle.