Publications

The viable application of soft electronics/robotics relies on the development of power devices which are desired to be flexible, deformable, or even self-healable. We report here a shape-adaptive, self-healable triboelectric nanogenerator (SS-TENG) for harvesting biomechanical energies. The use of a viscoelastic polymer, normally known as Silly Putty, as the electrification material and as the matrix of a carbon-nanotube-filled composite (CNT-putty) electrode endows the SS-TENG the capability of adapting to arbitrary irregular surfaces and instantaneous healing from mechanical damage (almost completely recovered in 3 min without extra stimuli). Furthermore, the output performances of the SS-TENG have also been significantly improved because (i) the ideal soft contact is achieved at the solid-solid interfaces for more effective contact electrification and (ii) the introduced cation dopants make the putty even more tribo-negative than polytetrafluoroethylene. The SS-TENG can be adhered to any curvy surface, tailored, and reshaped into arbitrary configurations and utilized as a power supply for small electronics, suggesting promising applications in soft electronics/robotics in the future.

Realizing active interaction with external environment/stimuli is a great challenge for current electronics. In this paper, a tribotronic tuning diode (TTD) is proposed by coupling a variable capacitance diode and a triboelectric nanogenerator in free-standing sliding mode. When the friction layer is sliding on the device surface for electrification, a reverse bias voltage is created and applied to the diode for tuning the junction capacitance. When the sliding distance increases from 0 to 25 mm, the capacitance of the TTD decreases from about 39 to 8 pF. The proposed TTD has been integrated into analog circuits and exhibited excellent performances in frequency modulation, phase shift, and filtering by sliding a finger. This work has demonstrated tunable diode and active analog signal modulation by tribotronics, which has great potential to replace ordinary variable capacitance diodes in various practical applications such as signal processing, electronic tuning circuits, precise tuning circuits, active sensor networks, electronic communications, remote controls, flexible electronics, etc.

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.

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.

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.

A low-cost high-performance solid-state flexible asymmetric supercapacitor (ASC) with α-MnO2 nanowires and amorphous Fe2O3 nanotubes grown on flexible carbon fabric is first designed and fabricated. The assembled novel flexible ASC device with an extended operating voltage window of 1.6 V exhibits excellent performance such as a high energy density of 0.55 mWh/cm(3) and good rate capability. The ASC devices can find numerous applications as effective power sources, such as powering color-switchable sun glasses and smart windows.

Abstract Tribovoltaic nanogenerators (TVNGs) have the characteristics of high current density, low matched impedance and continuous output, which is expected to solve the problem of power supply for small electronic devices. However, wear occurrence in friction interface will seriously reduce the performance of TVNGs as well as lifetime. Here, we employ MXene solution as lubricate to improve output current density and lifetime of TVNG simultaneously, where a high value of 754 mA m −2 accompanied with a record durability of 90,000 cycles were achieved. By comparing multiple liquid lubricates with different polarity, we show that conductive polar liquid with MXene as additive plays a crucial role in enhancing the electrical output performance and durability of TVNG. Moreover, the universality of MXene solution is well demonstrated in various TVNGs with Cu and P -type Si, and Cu and N -GaAs as material pairs. This work may guide and accelerates the practical application of TVNG in future.

We introduce an innovative design of a disk triboelectric nanogenerator (TENG) with segmental structures for harvesting rotational mechanical energy. Based on a cyclic in-plane charge separation between the segments that have distinct triboelectric polarities, the disk TENG generates electricity with unique characteristics, which have been studied by conjunction of experimental results with finite element calculations. The role played by the segmentation number is studied for maximizing output. A distinct relationship between the rotation speed and the electrical output has been thoroughly investigated, which not only shows power enhancement at high speed but also illuminates its potential application as a self-powered angular speed sensor. Owing to the nonintermittent and ultrafast rotation-induced charge transfer, the disk TENG has been demonstrated as an efficient power source for instantaneously or even continuously driving electronic devices and/or charging an energy storage unit. This work presents a novel working mode of TENGs and opens up many potential applications of nanogenerators for harvesting even large-scale energy.