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A self-powered, sliding electrification based quasi-static triboelectric sensor (QS-TES) for detecting angle from rotating motion is reported. This innovative, cost-effective, simply-designed QS-TES has a two-dimensional planar structure, which consists of a rotator coated with four channel coded Cu foil material and a stator with a fluorinated ethylenepropylene film. On the basis of coupling effect between triboelectrification and electrostatic induction, the sensor generates electric output signals in response to mechanical rotating motion of an object mounted with the sensor. The sensor can read and remember the absolute angular position, angular velocity, and acceleration regardless being continuously monitored or segmented monitored. Under the rotation speed of 100 r min−1, the output voltage of the sensor reaches as high as 60 V. Given a relatively low threshold voltage of ±0.5 V for data processing, the robustness of the device is guaranteed. The resolution of the sensor is 22.5° and can be further improved by increasing the number of channels. Triggered by the output voltage signal, the rotating characteristics of the steering wheel can be real-time monitored and mapped by being mounted to QS-TES. This work not only demonstrates a new principle in the field of angular measurement but also greatly expands the applicability of triboelectric nanogenerator as self-powered sensors.

A new membrane-based triboelectric sensor (M-TES) is presented as a self-powered pressure change sensor. It generates a voltage induced by surface triboelectric charges in response to an air pressure change. Extremely high detection resolutions of 0.34 Pa and 0.16 Pa are achieved when the air pressure increases and decreases in a small region away from the ambient standard atmosphere pressure, respectively, indicating an excellent sensitivity. By integrating the M-TES with a signal processing unit, we demonstrate practical applications of the device in sensing footsteps, respirations, and heartbeat, which suggests widespread use of the M-TES in fields of security surveillance, chemical engineering, geography research, environment monitoring, and personal healthcare.

The applications of a single-layer triboelectric nanogenerator (TENG) may be challenged by its lower output current, and a possible solution is to use three-dimensional (3D) integrated multilayered TENGs. However, the most important point is to synchronize the outputs of all the TENGs so that the instantaneous output power can be maximized. Here, a multi-layered stacked TENG is reported as a cost-effective, simple, and robust approach for harvesting ambient vibration energy. With superior synchronization, the 3D-TENG produces a short-circuit current as high as 1.14 mA, and an open-circuit voltage up to 303 V with a remarkable peak power density of 104.6 W m−2. As a direct power source, it is capable of simultaneously lighting up 20 spot lights (0.6 W ea.) as well as a white G16 globe light. Furthermore, compared with the state-of-the-art vibration energy harvesters, the 3D-TENG has an extremely wide working bandwidth up to 36 Hz in low frequency range. In addition, with specific dimensional design, the 3D-TENG is successfully equipped inside a ball with a diameter of 3 inches, using which 32 commercial LEDs are simultaneously lighted up via hand shaking, exhibiting great potential of scavenging the abundant but wasted kinetic energy when people play basketball, football, baseball, and so on.