Zisheng Xu

Electret materials are vital for low-frequency mechanical energy conversion; however, their practical outdoor deployment is severely restricted by moisture-induced charge decay and environmental screening. Herein, an electrostatic assembly technology is reported to construct a robust composite electret film featuring a self-encapsulated inner charge layer. By bringing a corona-charged fluorinated ethylene propylene (FEP) film into intimate contact with an uncharged secondary dielectric layer, interfacial charge redistribution and dielectric polarization establish a persistent interfacial electric field, generating a maximum interfacial shear holding strength of 3.50 N/cm2. Following this electrostatic assembly via corona-injected charges, the resulting self-encapsulated structure effectively shields the active charge carriers from moisture and screening. Based on this film, a composite droplet electret generator (C-DEG) is developed. Utilizing a transistor-like “bulk effect”, the C-DEG delivers a peak power of 0.25 mW at a 2 MΩ load under a single-droplet impact, maintaining a stable output for over 6000 s. This work provides a stable, packaging-free paradigm for resilient self-powered systems.

Highly efficient, low‐frequency (2 ) per cycle and a short‐circuit charge output of 1.21 mC (605 mC/m ² ) per cycle. Through reconfiguring output paths, the energy transfer efficiency can exceed 50%—far outperforming other energy management strategies. We demonstrate that this energy management strategy enables practical applications in powering low‐impedance electronic devices such as motors and batteries, paving the way for advanced self‐powered systems.

Dielectric elastomers (DEs) have promising capabilities for soft electromechanical systems, including those for actuation and energy generation. However, their widespread application is restricted by electromechanical instability (EMI) and the requirement for high‐voltage operation. This study presents a dual‐modal DE system that effectively overcomes these limitations by leveraging a dual‐membrane structure. The proposed structure not only suppresses EMI through charge sharing but also enables simultaneous energy harvesting and actuation, enhancing the overall electrical performance of the system. The system demonstrated a remarkable improvement in output performance, exceeding that of traditional single‐modal DE generators by up to 30%. The practicality of the system is developed by integrating it into a mechanically powered soft robot capable of locomotion and environmental monitoring using a wireless temperature sensor. This study paves the way for the development of advanced DE‐based systems with enhanced stability, functionality, and potential for diverse applications in soft robotics, energy harvesting, and other areas that require coupled electromechanical capabilities.

Numerous associated challenges arise with the advancement and continuous improvement of implantable medical devices, such as the frequent requirement for battery replacement. The flexible ultrasonic‐induced wireless energy conversion (UWEC) technology has garnered significant interest due to its superior energy transmission efficiency, safety, and biocompatibility compared to traditional electromagnetic wireless energy conversion technology. This paper provides a comprehensive review of the recent advancements in two types of flexible UWEC technologies, triboelectric nanogenerators, and piezoelectret nanogenerators, with a focus on their applications in implantable medical treatments. First, the energy conversion principles and general materials of flexible UWEC are presented. Then, the research and application of flexible UWEC devices are introduced in detail based on their medical functions. At the end of this review, perspectives and opportunities are discussed.

1. Pipeline flow is very important in the engineering field and has many applications, especially curved pipes being essential components of almost all the industrial process equipment, ranging fro...

Joint movement is a plentiful source of energy in living organisms; however, it is challenging to harvest due to its multidirectional nature, and effective technologies for harnessing this energy are lacking. In this study, a novel approach is presented to harvest joint motion energy by combining an alternating current dielectric elastomer generator (AC‐DEG) with an electret nanogenerator (ENG). The AC_ENG‐DEG, utilizing ion hydrogel electrodes and ENG, exhibits remarkable stretchability (860%) and efficiently converts mechanical energy into electrical energy through a stretch‐based mechanism. With only 37 cycles, the device reaches a saturation voltage of 1.18 kV and generates an output charge of 1.96 µC per cycle. Notably, the charge output response speed is approximately four times faster than that of traditional AC‐DEGs. The proposed strategy for harvesting human mechanical energy in this study represents a promising pathway for developing high‐performance energy harvesting devices and self‐powered systems.

Sleep monitoring based on triboelectric nanogenerator: wearable and washable approach