Publications

Abstract Based on the coupling effects of contact electrification and electrostatic induction, a triboelectric nanogenerator (TENG) can convert mechanical energy into electric power, which is at the cutting edge of alternative energy technology. Although a considerable number of TENGs with different configurations have been designed, some of them however, which only depend on the electrostatic induction effect have not received enough attention. Here, a non‐contact TENG model consists of copper rings and charged dielectric sphere is presented, which is aimed at exploring the working process of TENGs caused by electrostatic induction. Two classical models, including vertical and horizontal double copper rings models are also proposed. Relevant advanced and accurate models of TENGs have been established through the finite element method. We anticipate that the constructed model and theoretical analysis are helpful for the design of non‐contact model TENGs with complicated geometric construction, and expand their applications in various fields. image

Shore-based water wave energy produced by the impact of ocean waves on the coastline is a kind of clean and renewable energy. In this paper, a pendular-translational hybrid nanogenerator (PT-HNG) with two multilayer triboelectric nanogenerators and a spring base is proposed to harvest the wave energy. Pendular-translational movement mechanism is a sliding rail structure embedded with a permanent magnet, and the output is greatly improved compared to the previous pendular-pendular movement mechanism. Furthermore, the use of the spring base not only makes the device easy to install and fix but also increases the swing angle, which can better harvest the water wave energy. When the PT-HNG is used on the beach, a 33 μF capacitor can be charged to 4.3 V in 85 s. PT-HNG can be used to build self-powered wireless sensor networks to monitor the surrounding environment. This work proposes an innovative and efficient way to capture shore-based wave energy.

Abstract Wearable, flexible, and even stretchable tactile sensors, such as various types of electronic skin, have attracted extensive attention, which can adapt to complex and irregular surfaces, maximize the matching of wearable devices, and conformally apply onto human organs. However, it is a great challenge to simultaneously achieve breathability, permeability, and comfortability for their development. Herein, mitigating the problem by miniaturizing and integrating the sensors is tried. Highly flexible and stretchable coaxial structure fiber‐shaped triboelectric nanogenerators (F‐TENGs) with a diameter of 0.63 mm are created by orderly depositing conductive material of silver nanowires/carbon nanotubes and encapsulated polydimethylsiloxane onto the stretchable spandex fiber. As a self‐powered multifunctional sensor, the resulting composite fiber can convert mechanical stimuli into electrical signals without affecting the normal human body. Moreover, the F‐TENGs can be easily integrated into traditional textiles to form tactile sensor arrays. Through the tactile sensor arrays, the real‐time tactile trajectory and pressure distribution can be precisely mapped. This work may provide a new method to fabricate fiber‐based pressure sensors with high sensitivity and stretchability, which have great application prospects in personal healthcare monitoring and human–machine interactions.

We report an external force triggered field-effect transistor based on a free-standing piezoelectric fine wire (PFW). The device consists of an Ag source electrode and an Au drain electrode at two ends of a ZnO PFW, which were separated by an insulating polydimethylsiloxane (PDMS) thin layer. The working principle of the sensor is proposed based on the piezoelectric potential gating effect. Once subjected to a mechanical impact, the bent ZnO PFW cantilever creates a piezoelectric potential distribution across it width at its root and simultaneously produces a local reverse depletion layer with much higher donor concentration than normal, which can dramatically change the current flowing from the source electrode to drain electrode when the device is under a fixed voltage bias. Due to the free-standing structure of the sensor device, it has a prompt response time less than 20 ms and quite high and stable sensitivity of 2%/μN. The effect from contact resistance has been ruled out.

Implantable medical devices (IMDs) have become indispensable medical tools for improving the quality of life and prolonging the patient's lifespan. The minimization and extension of lifetime are main challenges for the development of IMDs. Current innovative research on this topic is focused on internal charging using the energy generated by the physiological environment or natural body activity. To harvest biomechanical energy efficiently, piezoelectric and triboelectric energy harvesters with sophisticated structural and material design have been developed. Energy from body movement, muscle contraction/relaxation, cardiac/lung motions, and blood circulation is captured and used for powering medical devices. Other recent progress in this field includes using PENGs and TENGs for our cognition of the biological processes by biological pressure/strain sensing, or direct intervention of them for some special self-powered treatments. Future opportunities lie in the fabrication of intelligent, flexible, stretchable, and/or fully biodegradable self-powered medical systems for monitoring biological signals and treatment of various diseases in vitro and in vivo.

We develop an Ag NPs@PDMS SERS substrate for detection of microorgnisms on a micron scale. The detection limit was up to 1 CFU/mL and the differentiation ability of this SERS substrate was evaluated for six different microorganisms. The machine learning algorithms were used for achieving automatic classification of microorganisms, with PCA-SVC model presents superior performance. Different from labeled SERS, label-free SERS technique is conducive to the discovery of unknown microorganisms in water environment. Therefore, this substrate is expected to be used for microbial system assessment and microbial safety monitoring in water environment combined with handheld Raman spectrometer and artificial intelligence.

Changes in hormone levels, improper lipid metabolism, and oxidative stress all significantly contribute to the pathogenic process of polycystic ovarian syndrome (PCOS). According to earlier research, pioglitazone and alpha-lipoic acid are crucial in the emergence of PCOS. The beneficial effects of pioglitazone and alpha-lipoic acid on PCOS were examined in the current study.The 120 patients with PCOS received three months of treatment in pioglitazone groups (n=40 case, 30 mg/time, 1 time/day), α-lipoic acid (n=40 case, 0.6 g/time, 1 time/day), and combination therapy (n=40 case, pioglitazone 30 mg/time, 1 time/day and α-lipoic acid, 0.6 g/time, 1 time/day). Before and after therapy, the following factors were evaluated: the hormonal profile, fasting serum insulin, body weight, body mass index (BMI), menstruation status, oxidative stress, and indications of lipid metabolism.The combination of pioglitazone and α-lipoic acid has a significantly improving effect on BMI, body weight, oxidative stress levels, lipid metabolism, and menstrual status. A significant increase in body weight, BMI, and follicle-stimulating hormone (FSH) levels were found in mice after being treated with α-lipoic acid alone. However, the use pioglitazone alone improves body weight, BMI, the calculation of insulin resistance index (HOMA-IR), Area under the curve (AUC)-insulin, fasting glucose/insulin (G/I) ratio, total testosterone, and malondialdehyde (MDA) levels in post-treatment than pre-treatment.These findings suggest that pioglitazone alone has a better effect than alpha-lipoic acid in improving oxidative stress levels, BMI, and menstrual cyclicity. Additionally, treatment with pioglitazone and alpha-lipoic acid did demonstrate a greater effect than monotherapy with each medication alone.