Vibration, widely existing in an ambient environment with a variety of forms and wide-range of scales, recently becomes an attractive target for energy harvesting. However, its time-varying directions and frequencies render a lack of effective energy technology to scavenge it. Here, we report a rationally designed nonlinear magnetoelectric generator for broadband and multi-directional vibration energy harvesting. By using a stabilized three-dimensional (3D) magnetic interaction and spring force, the device working bandwidth was largely broadened, which was demonstrated both experimentally and theoretically. The multidirectional vibration energy harvesting was enabled by three identical suspended springs with equal intersection angles, which are all connected to a cylindrical magnet. Numerical simulations and experimental results show that the nonlinear harvester can sustain large-amplitude oscillations over a wide frequency range, and it can generate power efficiently in an arbitrary direction. Moreover, the experimental data suggest that the proposed nonlinear energy harvester has the potential to scavenge vibrational energy over a broad range of ambient frequencies in 3D space.

Harnessing abundant kinetic water energy in diverse forms of river flows, ocean waves, tidal currents, raindrops, and others, is highly attractive to ease the energy crisis and satisfy the demands of scattered sensor network nodes in the Internet of things. Among them, raindrops, widely and ubiquitously distributed in nature and ambient living life, have been extensively explored and regarded as significant renewable energy carriers. Extensive efforts have been made to investigate droplet‐based electricity nanogenerators in fundamental mechanism, performance, and applications for achieving sustainable energy demands of the rapidly developing society over the past decade. In this review, we introduce the remarkable progress in this field and discuss the fundamental mechanisms of droplet energy harvesting technology for achieving high‐power generation. More significantly, a systematic review of droplet energy harvesting in different two‐phase interfaces, including liquid–solid, liquid–liquid, and liquid–gas interfaces, is provided. Finally, this survey reveals that droplet‐based electricity generators present vast potential in the power supply. At the same time, several development challenges and prospective solutions are discussed to spur future technological advancements.

A rotational multiple-phase direct-current triboelectric nanogenerator with low crest factor and high performance is presented for powering optical computing device forming the self-powered monitoring system.

Today, cardiovascular diseases threaten human health worldwide. In clinical practice, it has been concluded that analyzing the pulse waveform can provide clinically valuable information for the diagnosis of cardiovascular diseases. Accordingly, continuous and accurate monitoring of the pulse wave is essential for the prevention and detection of cardiovascular diseases. Wearable triboelectric nanogenerators (TENGs) are emerging as a pulse wave monitoring biotechnology due to their compelling characteristics, including being self-powered, light-weight, and wear-resistant, as well as featuring user-friendliness and superior sensitivity. Herein, a comprehensive review is conducted on the progress of wearable TENGs for pulse wave monitoring. Firstly, the four modes of operation of TENG are briefly described. Secondly, TENGs for pulse wave monitoring are classified into two categories, namely wearable flexible film-based TENG sensors and textile-based TENG sensors. Next, the materials, fabrication methods, working mechanisms, and experimental performance of various TENG-based sensors are summarized. It concludes by comparing the characteristics of the two types of TENGs and discussing the potential development and challenges of TENG-based sensors in the diagnosis of cardiovascular diseases and personalized healthcare.

Continuous and precise monitoring of pulse waveforms is essential for the prevention and early diagnosis of cardiovascular diseases. However, current pulse sensors suffer from significant motion artifacts caused by inadequate skin-device adhesion and poor interfacial conformability during physical activity. In this work, we develop a highly sensitive and conformal pressure sensor featuring an innovative island-bridge configuration capable of accurately measuring arterial pulse waveforms across multiple body artery sites, even under motion artifacts. Through finite element analysis and systematic experimental validation, the unique island-bridge design is demonstrated in achieving both superior signal fidelity and motion artifact suppression. The developed sensor shows a high-pressure sensitivity of 4.75 V/kPa, a rapid response time of less than 30 ms, and excellent durability over 6,000 cyclic loads. Furthermore, it has demonstrated exceptional performance in capturing pulse waveforms across multiple body sites, allowing the extraction of crucial cardiovascular parameters, even in the presence of motion artifacts. Given the remarkable advantages, our study presents a unique triboelectric sensor design that not only improves the sensitivity but also effectively eliminates motion artifacts, providing a promising solution for creating wearable pressure sensors for continuous cardiovascular monitoring.