Publications

The triboelectric properties of the tribolayers are essential factors affecting the current density of triboelectric nanogenerators (TENGs). To enhance the current density, composites have been developed to tune their triboelectric properties. Previous studies have reported enhanced TENG performance with composite materials, primarily based on their composition, while chemical interactions between the components have been less analyzed. In this study, we report a novel approach to improve the current density of a TENG by introducing dipole-dipole interactions between a nylon filter membrane and graphene oxide (GO) through hydrogen bonds. The Raman spectroscopy confirmed the occurrence of the interactions resulting from hydrogen bonding. The enhancing mechanisms of hydrogen bonds were further analyzed by Kelvin probe force microscope (KPFM) measurement, which demonstrated that hydrogen bonding could influence the surface potential of the coated GO, leading to increased output of the nylon/GO@NFM TENG (NGN-TENG). Our results show that an ultrahigh current density of 1757 mA·m−2 was obtained with a 2 × 2 cm2 NGN-TENG. Additionally, we demonstrated the feasibility of using the NGN-TENG as a motion sensor to sense finger motions. These findings suggest that the introduction of hydrogen bonds in TENG composites can provide a promising route for improving their performance.

In the Letter, we demonstrate an improved electroless plating method for the synthesis of bimetallic shell particles. The procedure involves a combination of surface reaction, seeding growth, and removal of supporting cores. We modified ammonical AgNO3 in ethanol with a controlled amount of HCHO in the seeding process and a uniform and relatively dense coverage of silver nanoparticle seeds on colloid cores was achieved. Following the second kind of metal plating, we extended this method to prepare continuous bimetallic core-shell and hollow particles with a submicrometer diameter. The morphologies of the bimetallic Cu/Ag and Pt/Ag particles were studied with transmission electron microscopy and scanning electron microscopy, and their crystallinity and chemical composition were confirmed by X-ray diffraction. The prepared materials may be of applied value in areas such as catalysis, optics, and plasmonics.

Abstract Wearable and portable electronics have brought great convenience. These battery‐powered commercial devices have a limited lifetime and require recharging, which makes more extensive applications challenging. Here, a battery‐like self‐charge universal module (SUM) is developed, which is able to efficiently convert mechanical energy into electrical energy and store it in one device. An integrated SUM consists of a power management unit and an energy harvesting unit. Compared to other mechanical energy harvesting devices, SUM is more ingenious, efficient and can be universally used as a battery. Under low frequency (5 Hz), a SUM can deliver an excellent normalized output power of 2 mW g −1 . After carrying several SUMs and jogging for 10 min, a commercial global positioning system module is powered and works continuously for 0.5 h. SUMs can be easily assembled into different packages for powering various commercial electronics, demonstrating the great application prospects of SUM as a sustainable battery‐like device for wearable and portable electronics.

Abstract Tribovoltaic nanogenerators (TVNGs) present great properties such as high direct‐current density and continuous output performance, which has great potential to solve the power supply problem for miniaturized electronic devices. However, the severe wear problem of TVNG causes rapid attenuation of current density, which is difficult to realize long‐term operation with high output. In this work, an effective strategy via interface lubrication is proposed to enhance the direct‐current density and lifetime of TVNGs simultaneously. The water‐based graphene oxide solution is utilized as a lubricant, which can increase the sliding surface carriers to enhance current density, and reduce the wear between the copper and the silicon wafer surface due to its excellent lubrication performance. Hence, the TVNG can generate peak current density output ≈775 mA m −2 , accompanied with 31 mC m −2 transfer charges density. The TVNG via interface lubrication can maintain high current output after 30 000 cycles. In addition, it can combine with triboelectric nanogenerator to constitute a dual‐type signal sensor, which can be used to monitor bridge vibration and goods’ weight. This study provides an effective method to solve the wear problem of TVNG and improve direct‐current density simultaneously, which will accelerate the practical application of TVNGs in the future.

The first bionic membrane sensor based on triboelectrification is reported for self-powered physiological and behavioral measurements such as local internal body pressures for non-invasive human health assessment. The sensor can also be for self-powered anti-interference throat voice recording and recognition, as well as high-accuracy multimodal biometric authentication, thus potentially expanding the scope of applications in self-powered wearable medical/health monitoring, interactive input/control devices as well as accurate, reliable, and less intrusive biometric authentication systems. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Abstract Researchers have devoted a lot of efforts on pursuing light weight and high flexibility for the wearable electronics, which also requires the related energy harvesting devices to have ultrathin thickness and high stretchability. Hence, an elastic triboelectric nanogenerator (TENG) is proposed that can serve as the second skin on human body. The total thickness of this TENG is about 102 µm and the device can work durably under a strain of 100%. The carbon grease is painted on the surface of elastomer film to work as stretchable electrode and thus the fine geometry control of the electrode can be achieved. This elastic TENG can even work on the human fingers without disturbing body movement. The open‐circuit voltage and short‐circuit current from the device with a contact area of 9 cm 2 can reach 115 V and 3 µA, respectively. Two kinds of self‐powered sensor systems with optimized identification strategies are also designed to demonstrate the application possibility of this elastic TENG. The superior characteristics of ultrathin thickness, high stretchability, and fine geometry control of this TENG can promote many potential applications in the field of wearable self‐powered sensory system, electronics skin, artificial muscles, and soft robotics.

Although silicon (Si) devices are the backbone of modern (opto-)electronics, infrared Si-photosensing suffers from low-efficiency due to its limitation in light-absorption. Here, we demonstrate a large improvement in the performance, equivalent to a 366-fold enhancement in photoresponsivity, of a Si-based near-infrared (NIR) photodetector (PD) by introducing the piezo-phototronic effect via a deposited CdS layer. By externally applying a −0.15‰ compressive strain to the heterojunction, carrier-dynamics modulation at the local junction can be induced by the piezoelectric polarization, and the photoresponsivity and detectivity of the PD exhibit an enhancement of two orders of magnitude, with the peak values up to 19.4 A/W and 1.8 × 1012 cm Hz1/2/W, respectively. The obtained maximum responsivity is considerably larger than those of commercial Si and InGaAs PDs in the NIR waveband. Meanwhile, the rise time and fall time are reduced by 84.6% and 76.1% under the external compressive strain. This work provides a cost-effective approach to achieve high-performance NIR photosensing by the piezo-phototronic effect for high-integration Si-based optoelectronic systems.