Publications

Acceleration sensors have a wide variety of applications for industrial engineering, biology and navigation.However, passive sensing, narrow detection range, large size, and high manufacturing cost curb their further development.Here, we present a miniaturized acceleration sensor (MAS) with rationally patterned electrodes, based on the single electrode triboelectric mechanism, featuring small size, high accuracy, large detection scale, and environmental friendliness.A stainless-steel ball, as the moving part of the MAS, experiences physical movement that is converted into an electrical signal.Equipped with rationally patterned electrodes, the MAS retains the smallest size and lowest weight compared with the currently reported self-powered acceleration sensors.Benefiting from the voltage-relationship-based direction detection mechanism, eight directions can be identified by one TENG module.Consequently, rotated 22.5° relatively, two TENG modules enable the MAS to detect 16 directions.Moreover, accelerations ranging from 0.1 m/s 2 to 50 m/s 2 can be identified according to the relationship of response time and accelerations in the horizontal direction.The relationship is obtained through the measurements of the sum of output voltages (VSOC) for the four bottom electrodes with varying accelerations.In addition, no distinct decrease of VSOC is observed after continuously operating for 2000 circles, presenting excellent robustness.Hence, this cost-effective and rationally patterned MAS reveals great potential for human machine interaction, VR/AR (virtual/augmented reality), sports training, and smart city.

With the continuous development of mechanical automation field, its monitoring technology is also changing with each passing day. Pneumatic technology is one of the important ways to realize mechanical automation. Here, the integrated real-time pneumatic monitoring system (PMS) is proposed, which is composed of a triboelectric linear displacement sensor (TLDS) and a cylinder. The resolution of TLDS is 100 μm, which is composed of a slider and a stator. According to theory of freestanding triboelectric nanogenerator (TENG), the working principle of TLDS is explained. Therefore, the proposed PMS can realize displacement and speed monitoring of the full stroke of the cylinder. The experimental results show that the PMS enabled accurate monitoring of cylinder displacement and speed under different pressure conditions, and the mean error rate of PMS is less than 2%. In addition, to fulfill the actual demands of the pneumatic industry, the real-time hardware processing module is designed to realize real-time monitoring. Finally, the PMS still has stable monitoring performance after 6 h (about 4 km) continuous operation. This work successfully explored the application of triboelectric sensors in pneumatic system and reached the requirements of industrial applications.

'Piezoresistance' published in 'Encyclopedia of Nanotechnology'

No abstract is provided for this article.

'Plasmon Resonance Energy Transfer Nanospectroscopy' published in 'Encyclopedia of Nanotechnology'

Developing flexible and sustainable power sources for multifunctional and self-powered sensors is crucial for electronic skin. Herein, we report a versatile, ultraflexible, high sensitivity, fish bladder film-based triboelectric nanogenerator (FBF-TENG) for smart electronic skin. A salient feature of the FBF-TENG is that a natural material acts as a triboelectric layer, which has good biocompatibility and degradability. The FBF-TENG exhibits good electrical performance for collecting biological energy, with output current density and charge density of nearly 4.56 mA/m2 and 25 μC/m2, respectively. In addition, the FBF-TENG-based electronic skin can respond linearly to acceleration and humidity with good sensitivity of about 446 nA·s2/m and 50 nA/% RH. Interestingly, the as-prepared FBF-TENG-based electronic skin also presents sensing performance of noncontact position in the range of 0–27 mm. These multifunctional advantages make it ideal for many applications, including human–machine interfacing, intelligent interfaces, and prosthetics.

The drastic expansion of consumer electronics (like personal computers, touch pads, smart phones, etc.) creates many human–machine interfaces and multiple types of interactions between human and electronics. Considering the high frequency of such operations in our daily life, an extraordinary amount of biomechanical energy from typing or pressing buttons is available. In this study, we have demonstrated a highly flexible triboelectric nanogenerator (TENG) solely made from elastomeric materials as a cover on a conventional keyboard to harvest biomechanical energy from typing. A dual-mode working mechanism is established with a high transferred charge density of ∼140 μC/m2 due to both structural and material innovations. We have also carried out fundamental investigations of its performance dependence on various structural factors for optimizing the electric output in practice. The fully packaged keyboard-shaped TENG is further integrated with a horn-like polypyrrole-based supercapacitor as a self-powered system. Typing in normal speed for 1 h, ∼8 × 10–4 J electricity could be stored, which is capable of driving an electronic thermometer/hydrometer. Our keyboard cover also performs outstanding long-term stability, water resistance, as well as insensitivity to surface conditions, and the last feature makes it useful to research the typing behaviors of different people.

Abstract Since circular motion becomes an important part of automated circulation equipment, a sliding triboelectric circular motion sensor (S‐TCMS) has been demonstrated to monitor the velocity and displacement of a circular motion. The S‐TCMS consists of the stator and slider, which is integrated with automated circular motion equipment for sensing applications. When the slider of PTFE grid slides between the stator's electrodes, four electrical signals are produced in the staggered electrode. The experimental results show that the voltage amplitude remains constant at different sliding velocities, showing good sensing stability. Also, this work proposes a real‐time hardware signal processing method, which converts the original S‐TCMS signal into two standard square wave signals. The method makes the sensing detection of S‐TCMS independent from electrostatic instrument and reduces the occupation of hardware resources. The sensing experimental results show that S‐TCMS can detect the velocity of circular motion with the maximum velocity deviation rate of less than 0.37%, the angular position sensing detection accuracy of 0.42°. The S‐TCMS shows good circular motion‐sensing characteristics after hardware signal processing.

The synthesis of carbon nanotubes (CNTs) by cobalt-catalyzed pyrolysis of thiophene has been investigated and optimized. The yield and the morphology of the synthesized product are highly sensitive to the experimental conditions. A synthesis temperature of 1000 °C is required for the decomposition of thiophene. The morphology and microstructure of the product are controlled by the thiophene vapor concentration and flow rate. High concentration of thiophene vapor deactivates the catalyst and results in the formation of carbon nanofibers or short CNTs with bad graphitization; the optimum thiophene concentration for CNTs growth is around 0.76−1%. Thiophene vapor at high flow rate produces Y-junction and multibranched CNTs. Three formation routes are proposed to illuminate the growth mechanism of the branched CNTs.