Search

The emerging tribovoltaic nanogenerators (TVNGs) has garnered considerable attention in recent years owing to its higher power density, but it is still limited by unstable output, mismatched impedance, and lower charging speed. Herein, a power‐managed GaN‐based TVNG is first proposed and a self‐powered wireless temperature monitoring system (SWTMS) is developed. The energy backflow from transition capacitor to TVNG is effectively suppressed by applying a high‐voltage‐resistant diode. Benefiting from the combination of the maximum power point tracking (MPPT and the buck converter, an autonomous power management unit (PMU) is designed. The internal impedance of TVNG with PMU decreases by ten times and the charging speed of capacitor increases by 7.18 times compared to those without PMU. Moreover, 100 LEDs and six parallel thermohygrometers can be constantly powered. The wireless temperature monitoring in industrial environments without external power supply is demonstrated through the developed SWTMS. This work proposes an effective power management strategy for TVNG with high output voltage, which exhibits great potential to promote the development of self‐powered sensors and Industrial Internet of Things (IIoT). [ABSTRACT FROM AUTHOR]

Body area network has attracted extensive attention for its applications in athletics, medical, diagnosis, and rehabilitation training in the next generation personalized health care solutions. Here, a contact‐separation direct current triboelectric nanogenerators (CSDC‐TENGs) based self‐powered wireless body area network (SWBAN) is reported that enables multi‐joint movements monitoring for human motion. The CSDC‐TENG is designed as a flexible active sensor with an internal contact switch, and the flexible substrate makes the TENG‐sensor stick onto skin easily. Due to the internal switch, the CSDC‐TENG could generate a DC current, a large instantaneous output voltage exceeds 700 V, and an instantaneous power can reach 1.076 W, which is more than 23 000 times higher than that of the traditional contact‐separation mode TENG in same size and materials without the switch. By coupling with flexible coil, the fixed high‐frequency radio signals can be modulated and emitted clearly ranging from 6 to 16 MHz, which can be wirelessly received and demodulated through a reader. Moreover, the SWBAN is demonstrated in a real time monitoring system for joints motion. This work has realized the wearable TENG for self‐powered wireless real‐time monitoring of body movements driven by low‐frequency human daily activities, which may promote a tremendous development of intelligent healthcare, wireless sensing system and body area network. [ABSTRACT FROM AUTHOR]

The triboelectric nanogenerator (TENG) which could convert mechanical energy into electrical energy has attracted worldwide attention in energy harvesting and the Internet of Things (IoTs). However, the extreme performance degradation in high-humidity environments is a big challenge. Here, a humidity-enhanced silicon-based semiconductor tribovoltaic direct-current nanogenerator (TVNG) is reported. The transferred charge and peak power in high-humidity environments (RH 90%) can reach 12.6 mC m−2 and 1.6 mW m−2, which are nearly 88 times and 100 times of those in low humidity (RH 30%), respectively. In particular, the TVNG achieves a milestone of transferred charge density, which is 4 times that of the previously reported traditional polymer TENG in high-humidity environments (RH 90%). The mechanism of performance improvement for the TVNG in high-humidity environments is analyzed in detail, which is attributed to the coupling effect of the enhanced surface states and reduced contact resistance. This research provides an effective approach to promote the output performance of a TVNG, which demonstrates the great application potential of the semiconductor tribovoltaic effect in high-humidity environmental energy harvesting such as oceans, rains, etc. [ABSTRACT FROM AUTHOR]