As a reliable indicator of human physiological health, respiratory rate has been utilized in more and more cases for prediction and diagnosis of potential respiratory diseases and the respiratory dysfunction caused by cystic fibrosis. However, compared with smart mobile electronics, traditional clinical respiration monitoring systems is not convenient to work as a household wearable device for real-time respiration monitoring in daily life due to its cumbersome structure, complex operability, and reliance on external power sources. Thus, we propose a wearable wireless respiration sensor based on lateral sliding mode triboelectric nanogenerator (TENG) to monitor respiratory rates by sensing the variation of the abdominal circumference. In this paper, we validate the possibility of the device as a respiration monitoring sensor via an established theoretical model and investigate the output performance of the sensor via a series of mechanical tests. Furtherly, the applications of the respiration sensor in different individuals, different breathing rhythms, different active states, and wireless transmission have been verified by a lot of volunteer tests. All the results demonstrate the potential of the proposed wearable sensor as a new alternative for detecting and monitoring real-time respiratory rates with general applicability and sensitivity.

Relationship management among different stakeholder groups plays an increasingly important role in construction innovation, which could explain the growing interest in stakeholder relationship studies of construction projects (SRCP) over the last two decades. However, most of the recent literature review studies have focused on stakeholder management, and there are very few studies systematically describing what types of relationships actually exist in construction projects. To fill the gap, a mixed-methods review is conducted to explore the state-of-the-art work on SRCP. 312 relevant peer-reviewed journal articles published between 2000 and 2022 were examined and analyzed using data from the Scopus and Web of Science databases. A follow-up systematic review of the identified literature was conducted with three main objectives: identifying the main research category, summarizing the main research topics, and proposing future research directions. It was found that over the past 20 years, SRCP has been extended to a greater variety of research topics, such as information technology, which needs to take into account the multi-dimensional research agendas. Overall, this study contributes to the research field in the SRCP domain by offering insightful information on the current state of SRCP and proposing potential future directions for research.

Piezoelectric semiconductors (PSs) are the most promising building blocks for multifunctional electronic devices due to the polarization field resulting from piezoelectricity and pyroelectricity. In this article, we investigate the electromechanical coupling behaviors of a hollow PS composite (HPSC) cylinder under a uniform temperate change. The HPSC cylinder is consist of an outer thin PS layer and an inner elastic layer. Taking the interactions of thermoelasticity, piezoelectricity, and pyroelectricity into account, we develop one-dimensional equations for the HPSC cylinder with axisymmetric deformation, and present analytical solutions of the physical fields in the HPSC cylinder with perfect and imperfect interfaces for different boundary conditions. For the static equilibrium equation of the PS layer, the approximate relationship between the electric field and the average electric field is employed. The effects of geometrical parameters and imperfect interface, as well as the tuning effect of thermal loadings, on the multifield coupling responses and piezotronic effects of the HPSC cylinder are discussed in detail. The numerical results show that the physical fields are sensitive to the thermal loading, and the geometrical parameters, boundary conditions, and the interface bonding condition play an important role in the design of PS devices.

Under the trend of the rapid development of the internet of things (IoT), sensing for dynamic behaviors is widely needed in many fields such as traffic management, industrial production, medical treatment, building health monitoring, etc. Due to the feature of power supply independence and excellent working performance under a low-frequency environment, triboelectric nanogenerators (TENGs) as sensors are attracting more and more attention. In this paper, a comprehensive review focusing on the recent advance of TENGs as sensors for dynamic behaviors is conducted. The structure and material are two major factors affecting the performance of sensors. Different structure designs are proposed to make the sensor suitable for different sensing occasions and improve the working performance of the sensors. As for materials, new materials with stronger abilities to gain or lose electrons are fabricated to obtain higher surface charge density. Improving the surface roughness of material by surface engineering techniques is another strategy to improve the output performance of TENG. Based on the advancement of TENG structures and materials, plenty of applications of TENG-based sensors have been developed such as city traffic management, human–computer interaction, health monitoring of infrastructure, etc. It is believed that TENG-based sensors will be gradually commercialized and become the mainstream sensors for dynamic sensing.