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Traditional humidity sensors for respiration monitoring applications have faced technical challenges, including low sensitivity, long recovery times, high parasitic capacitance and uncalibrated temperature drift. To overcome these problems, we present a triple-layer humidity sensor that comprises a nanoforest-based sensing capacitor, a thermistor, a microheater and a reference capacitor. When compared with traditional polyimide-based humidity sensors, this novel device has a sensitivity that is improved significantly by 8 times within a relative humidity range of 40–90%. Additionally, the integration of the microheater into the sensor can help to reduce its recovery time to 5 s. The use of the reference capacitor helps to eliminate parasitic capacitance, and the thermistor helps the sensor obtain a higher accuracy. These unique design aspects cause the sensor to have an excellent humidity sensing performance in respiration monitoring applications. Furthermore, through the adoption of machine learning algorithms, the sensor can distinguish different respiration states with an accuracy of 94%. Therefore, this humidity sensor design is expected to be used widely in both consumer electronics and intelligent medical instrument applications.

Circulating tumor cells (CTCs), a type of cancer cell that spreads from primary tumors into human peripheral blood and are considered as a new biomarker of cancer liquid biopsy. It provides the direction for understanding the biology of cancer metastasis and progression. Isolation and analysis of CTCs offer the possibility for early cancer detection and dynamic prognosis monitoring. The extremely low quantity and high heterogeneity of CTCs are the major challenges for the application of CTCs in liquid biopsy. There have been significant research endeavors to develop efficient and reliable approaches to CTC isolation and analysis in the past few decades. With the advancement of microfabrication and nanomaterials, a variety of approaches have now emerged for CTC isolation and analysis on microfluidic platforms combined with nanotechnology. These new approaches show advantages in terms of cell capture efficiency, purity, detection sensitivity and specificity. This review focuses on recent progress in the field of nanotechnology-assisted microfluidics for CTC isolation and detection. Firstly, CTC isolation approaches using nanomaterial-based microfluidic devices are summarized and discussed. The different strategies for CTC release from the devices are specifically outlined. In addition, existing nanotechnology-assisted methods for CTC downstream analysis are summarized. Some perspectives are discussed on the challenges of current methods for CTC studies and promising research directions.

An intelligent humidity sensing system has been developed for real-time monitoring of human behaviors through respiration detection. The key component of this system is a humidity sensor that integrates a thermistor and a micro-heater. This sensor employs porous nanoforests as its sensing material, achieving a sensitivity of 0.56 pF/%RH within a range of 60–90% RH, along with excellent long-term stability and superior gas selectivity. The micro-heater in the device provides a high operating temperature, enhancing sensitivity by 5.8 times. This significant improvement enables the capture of weak humidity variations in exhaled gases, while the thermistor continuously monitors the sensor’s temperature during use and provides crucial temperature information related to respiration. With the assistance of a machine learning algorithm, a behavior recognition system based on the humidity sensor has been constructed, enabling behavior states to be classified and identified with an accuracy of up to 96.2%. This simple yet intelligent method holds great potential for widespread applications in medical assistance analysis and daily health monitoring.

Flexible humidity sensors, as pivotal sensing components in the Internet of Things and intelligent era, have achieved significant progress in material innovation, fabrication engineering, and application diversification in recent years. This review systematically presents the current research status of flexible humidity sensors, focusing on the influence of novel humidity-sensitive materials(including polymers, metal oxides, carbon-based materials, and two-dimensional materials) on key performance metrics such as sensitivity, response time, and stability. The optimization effects of fabrication technologies such as screen printing, spraying, and deposition on device performance are also analyzed. Furthermore, the innovative applications of flexible humidity sensors in fields including healthcare, smart agriculture, smart homes, and human-machine interaction are elaborated in detail. These applications highlight the sensors’ adaptability to diverse environmental requirements and their potential to enable intelligent monitoring and interactive systems. Finally, future technological directions for flexible humidity sensors are proposed from the perspectives of material system innovation, improvement of multi-parameter collaborative sensing performance, and optimization of adaptability to complex environments. The proposed development directions are targeted at achieving higher precision, multifunctionality, and self-powered operation, providing insights and guidance for the research and development of next-generation flexible intelligent sensing devices. By bridging material science, manufacturing engineering, and application engineering, this comprehensive review provides a forward-looking perspective on advancing flexible humidity sensing technologies for emerging intelligent systems.

Vacuum equipment has a wide range of applications, and vacuum monitoring in such equipment is necessary in order to meet practical applications. Pirani sensors work by using the effect of air density on the heat conduction of the gas to cause temperature changes in sensitive structures, thus detecting the pressure in the surrounding environment and thus vacuum monitoring. In past decades, MEMS Pirani sensors have received considerable attention and practical applications because of their advances in simple structures, long service life, wide measurement range and high sensitivity. This review systematically summarizes and compares different types of MEMS Pirani sensors. The configuration, material, mechanism, and performance of different types of MEMS Pirani sensors are discussed, including the ones based on thermistors, thermocouples, diodes and surface acoustic wave. Further, the development status of novel Pirani sensors based on functional materials such as nanoporous materials, carbon nanotubes and graphene are investigated, and the possible future development directions for MEMS Pirani sensors are discussed. This review is with the purpose to focus on a generalized knowledge of MEMS Pirani sensors, thus inspiring the investigations on their practical applications.

Polysilicon is widely used as a thermoelectric material due to its CMOS compatibility and tunability through doping. The accurate measurement of the thermoelectric parameters—such as the Seebeck coefficient, thermal conductivity, and electrical resistivity—of polysilicon with various doping conditions is essential for designing and fabricating high-performance thermopile sensors. This work presents an all-in-one testing chip that incorporates double-layer thermoelectric structures on a suspended membrane-based supporting layer, with polysilicon constituting at least one of these thermoelectric layers. By employing a differential calculation approach in conjunction with thermal imaging methods, we could simultaneously measure various thermoelectric parameters—including resistivity, the Seebeck coefficient, and thermal conductivity—of polysilicon under different doping conditions. Furthermore, the method proposed in this study provides a means for accurately obtaining thermoelectric parameters for other materials, thereby facilitating the design and optimization of thermoelectric devices.

In this work, a N/P polySi thermopile-based gas flow device is presented, in which a microheater distributed in a comb-shaped structure is embedded around hot junctions of thermocouples. The unique design of the thermopile and the microheater effectively enhances performance of the gas flow sensor leading to a high sensitivity (around 6.6 μV/(sccm)/mW, without amplification), fast response (around 35 ms), high accuracy (around 0.95%), and mood long-term stability. In addition, the sensor has the advantages of easy production and compact size. With such characteristics, the sensor is further used in real-time respiration monitoring. It allows detailed and convenient collection of respiration rhythm waveform with sufficient resolution. Information such as respiration periods and amplitudes can be further extracted to predict and alert of potential apnea and other abnormal status. It is expected that such a novel sensor could provide a new approach for respiration monitoring related noninvasive healthcare systems in the future.

Heat stroke (HS) is a life-threatening condition with limited preventive options. Inspired by the classical Qingshu Yiqi Decoction, this study developed a palatable health tea Xiao Qingshu Yiqi Decoction (XQYD) using exclusively medicine-food homology substances—licorice root, bamboo leaves, lotus stalk, and watermelon rind. The extraction process was optimized via response surface methodology, yielding optimal conditions of 70°C, 63.5 min, and a 10:1 liquid-solid ratio. In a rat model of heat stroke, XQYD pretreatment significantly increased survival rates to 100% and alleviated oxidative damage by modulating serum SOD, MDA, and NR levels, while down-regulating hepatic HSP70 overexpression. UPLC-MS/MS analysis identified 29 bioactive compounds, with glycyrrhizin as the most abundant constituent. Network pharmacology and molecular docking analyses suggested that the observed protective effects may be mediated through key targets including AKT1, TNF, and CASP3. Crucially, an acute oral toxicity test demonstrated an excellent safety profile, with no adverse effects observed at 30 g/kg and no pathological lesions in major organs. This study successfully transformed a classical formula into a consumer-friendly health product, offering a safe, effective, and naturally-derived strategy for heat stroke prevention.

Frequent extreme heat events around the world not only pose a major threat to human health but also cause significant economic losses to the livestock industry. The existing management practices are insufficient to fully prevent heat stress with an urgent need to develop preventive medicines. The aim of this study was to develop an anti-heat stress Chinese herbal formula (CHF) via big data analysis techniques and to evaluate its anti-heat stress effect and mechanism of action via pharmacodynamic evaluation and network pharmacology analysis. Many anti-heat stress CHFs were collected from the Chinese National Knowledge Infrastructure (CNKI) database. Three alternative CHFs were obtained via unsupervised entropy hierarchical clustering analysis, and the most effective CHF against heat stress, Shidi Jieshu decoction (SJD), was obtained by screening in a mouse heat stress model. In dry and hot environments, SJD significantly improved the heat tolerance of AA broilers by 4–6°C. In a humid and hot environment, pretreatment with 2% SJD resulted in 100% survival of Wenchang chickens at high temperatures. The main active ingredients of SJD were identified as muntjacoside E, timosaponin C, macrostemonoside H and mangiferin via ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) and database comparison. The active ingredients of SJD were found to target tumor necrosis factor-α (TNF-α), signal transducer activator of transcription 3 (STAT3) and epidermal growth factor receptor (EGFR). Finally, the safety of the new formulation was assessed in an acute oral toxicity study in rats. The SJDs developed in this study provide a new option for the prevention of heat stress in animal husbandry and offer new insights for further research on anti-heat stress. Highlights 1. Shidi Jieshu decoction (SJD) increases the heat tolerance of animals. 2. SJD increased the survival rate of Wenchang chickens under heat stress to 100%. 3. SJD can be used to prevent heat stress in animals and humans. 4. EGFR and STAT3 may be novel anti-heat stress targets in addition to inflammation.

A thermopile detector with their thermocouples distributed in micro-bridges is designed and investigated in this work. The thermopile detector consists of 16 pairs of n-poly-Si/p-poly-Si thermocouples, which are fabricated using a low-cost, high-throughput CMOS process. The micro-bridges are realized by forming micro trenches at the front side first and then releasing the silicon substrate at the back side. Compared with a thermopile device using a continuous membrane, the micro-bridge-based one can achieve an improvement of the output voltage by 13.8% due to a higher temperature difference between the hot and cold junctions as there is a decrease in thermal conduction loss in the partially hollowed structure. This technique provides an effective way for developing high-performance thermopile detectors and other thermal devices.