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Textile-based triboelectric nanogenerators (TENGs) hold considerable promise as sustainable power sources for wearable electronics, yet their seamless integration into everyday clothing remains a challenge. This paper introduces a scalable woven TENG structure that utilizes core−shell yarns composed of commercially available wool and polyester with an inner copper electrode. The device achieves notable performance with an output voltage of 18.5 V, a current of 3.7 µA, and a power density of 51 mW/m2. The novel multilayer design combines hybrid single-electrode and contact-separation approaches, significantly enhancing triboelectric performance and the device's durability. The multilayer functionality amplifies energy conversion efficiency by increasing the contact area and optimizing charge accumulation through multiple interacting layers. This advanced textile TENG is comfortable, flexible, and aesthetically pleasing while being compatible with large-scale textile manufacturing processes. It demonstrates excellent washability, durability under diverse weather conditions, and resilience to repeated mechanical loading. Highly responsive to a broad range of forces, from gentle taps to strong impacts, this TENG is versatile for body motion monitoring and wearable applications. It represents a significant advancement in creating practical, efficient, and durable energy-harvesting textiles, with promising applications in garment production for precise motion detection, such as for professional athletes and individuals requiring specialized monitoring. [ABSTRACT FROM AUTHOR]

Copyright of China Synthetic Fiber Industry is the property of Sinopec Baling Petrochemical Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Flexible electronics show wide application prospects in electronic skin, health monitoring, and human–machine interfacing. As an essential part of flexible electronics, flexible pressure sensors have become a compelling subject of academic research. There is an urgent need to develop piezoelectric sensors with high sensitivity and stability. In this work, the high flexibility of polylactic acid (PLA) film and the excellent ferroelectric properties and high dielectric constant of tetragonal barium titanate (BTO) led to their use as filling materials to fabricate flexible piezoelectric composite films by spinning coating. PLA is used to produce flexible binding substrates, and BTO is added to the composite to enhance its electrical output by improving its piezoelectric performance. The peak output voltage of the PLA/BTO tetragonal piezoelectric film is 22.57 V, and the maximum short-circuit current was 3041 nA. Durability tests showed that during 40,000 s of continuous operation, in the range of 15~120 kPa, the linear relationship between pressure and the film was excellent, the sensitivity for the output voltage is 0.176 V/kPa, and the output current is 27.77 nA/kPa. The piezoelectric pressure sensor (PPS) also enables accurate motion detection, and the extensive capabilities of the PENG highlight its potential in advancing motion sensing and human–computer interactions. [ABSTRACT FROM AUTHOR]

Pressure sensors for monitoring human motion are gaining increasing attention, and wearable devices with good flexibility and high sensitivity are urgently needed in the field of motion monitoring. Here, a graphene-based pressure sensor was fabricated by combining prestretching and laser reduction strategy. This method not only gives the graphene oxide layer a gradient-wrinkled structure but also introduces a swelling porous structure into it. The multilevel microporous gradient-wrinkled structure provides the sensor with a broad detection range (33 Pa–6.67 kPa), a low detection limit (33 Pa), and high sensitivity (125.9 ± 10.8 kPa–1). Furthermore, the sensor has good mechanical stability and a short response time. More importantly, the potential application of the prepared sensor in monitoring a wide range of motion is demonstrated, such as finger and wrist flexion movements. [ABSTRACT FROM AUTHOR]

Human physical activity monitoring plays a crucial role in promoting personalized health management. In this work, inspired by an ancient Chinese belt, a belt-type wearable sensor (BWS) based on a triboelectric nanogenerator (TENG) is presented to monitor daily movements and collect the body motion mechanical energy. The developed BWS consists of a soft silicone sheet and systematically connected sensing units made from triboelectric polymer materials including polytetrafluoroethylene (PTFE) and polyamide (PA). A parameter study of the sensing units is firstly conducted to optimize the structure of BWS. The experimental studies indicate that the parameter-optimized BWS unit achieves a maximum output voltage of 47 V and a maximum current of 0.17 μA. A BWS with five sensing units is manufactured to record body movements, and it is able to distinguish different physical activities including stillness, walking, running, jumping, normal breathing, cessation of breathing, and deep breathing. In addition, the developed BWS successfully powers electronic devices including a smartphone, digital watch, and LED lights. We hope this work provides a new strategy for the development of wearable self-powered intelligent devices. [ABSTRACT FROM AUTHOR]

This study investigates the application of textile electrodes using PANI (Polyaniline) conductive material for motion sensing, specifically aimed at motion monitoring for the elderly. By depositing a PANI conductive layer on the base of warp-knitted fabric through in-situ polymerization and plasma treatment, a PCCWKF (Polyaniline Coated Conductive Warp-Knitted Fabric) with enhanced electrical conductivity and mechanical flexibility was developed. The research optimized the electrical resistivity and durability of PCCWKF by incorporating Polyvinyl Alcohol (PVA) as a toughening agent, improving the adhesion of the PANI conductive layer to the textile substrate. The sensor's efficacy in accurately recording and monitoring motion amplitude and frequency in real-time was demonstrated through its application in smart clothing, focusing on respiratory, elbow, and knee motion monitoring. This study holds significant implications for the advancement of wearable technology and smart textiles in the health monitoring of the elderly. [ABSTRACT FROM AUTHOR]

Sarcopenia recognition is very crucial in the early diagnosis of sarcopenia. However, the commonly used screening methods are limited by real‐time property, portability, and convenient usability at home. Herein, an electrospun BaTiO3 film is proposed and a piezoelectric sensor with silver electrodes and polyimide substrates is fabricated. The sensor exhibits high piezoelectricity (74.2 pC N−1), sensitivity, linearity, low detection limit (0.2 mN), and significant bending ability (bending angle can exceed 90°), maintaining stable output after more than 20 000 cycles during a week. Due to its excellent performance, the piezoelectric sensor to the recognition of sarcopenia is applied and a wearable system to collect piezoelectric signals from the lower limb movements of the elderly is developed. By selecting features from these signals, eight kinds of machine learning models are employed and their performances in recognizing sarcopenia are compared in both male and female groups. The results indicate that the artificial neural network (ANN) model has the highest performance, with accuracies of 92.9% in males and 98.1% in females. This piezoelectric sensor, combined with a wireless communication module, is expected to provide crucial evidence for sarcopenia detection, offering a new, convenient, and household screening solution for early diagnosis and prevention of sarcopenia. [ABSTRACT FROM AUTHOR]

Bio‐compatible strain sensors are indispensable for human monitoring devices, requiring a delicate balance of robustness, flexibility, and sensitivity. However, achieving these attributes concurrently remains a formidable challenge. This article presents a pioneering approach to fabricate three‐dimensional flexible strain sensors using laser‐induced graphene (LIG) on polyimide (PI) substrates. Through a one‐step laser direct writing (LDW) technique, durable LIG/CuSO4 composites with closed‐pore porous structures are synthesized. The integration of copper sulfate within the closed‐cell architecture of LIG establishes a resilient conducting pathway, enhancing sensitivity to deformation under tensile stress. The resulting sensor exhibits exceptional performance in monitoring a wide range of human movements, from vigorous activities to subtle oscillations and physiological signals. Notably, the sensor boasts a remarkable sensing range of up to 25% strain, coupled with a high sensitivity characterized by a gauge factor of approximately 597. Rapid response times of 175 ms and quick recovery times of 200 ms further underscore its efficiency. Moreover, the sensor demonstrates outstanding stability and durability, maintaining consistent performance over 5600 cyclic experiments. This innovative approach represents a significant advancement in bio‐compatible strain sensor technology, offering a versatile solution for diverse monitoring applications. [ABSTRACT FROM AUTHOR]

Copyright of Micronanoelectronic Technology is the property of Micronanoelectronic Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The traditional basketball training monitoring method has some limitations, such as relying on manual judgment and subjective evaluation, and being limited by equipment and environmental conditions. In order to solve these problems, an optical sensor system is designed and constructed in this study, which can capture the optical signals during basketball training in real time and convert them into digital data. These data are analyzed and processed using deep learning algorithms to extract features related to basketball training. A large number of experiments and tests have verified the effectiveness and accuracy of this optical sensor method. The experimental results show that this method can monitor and record the key information of basketball movement track, players' movements and skills in real time, and can quantitatively evaluate the quality and effect of basketball training. Through the combination of deep learning technology and optical sensors, non-invasive, high-precision and real-time monitoring can be achieved, which provides a powerful auxiliary and evaluation means for the training of basketball players, and helps to improve the training effect and level. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the new era of artificial intelligence (AI) and the Internet of Things (IoT), big data collection and analysis for intelligent sports are of great importance in monitoring human health. Herein, naturally, biodegradable triboelectric nanogenerators (NB‐TENGs) are developed based on low‐cost, recyclable, and environmentally friendly corn bracts, which are further applied in neck motion recognition. Three NB‐TENGs are integrated into an elastic collar to create a neck‐condition monitoring triboelectric sensor (NCM‐TS). An intelligent behavioral monitoring system is achieved by combining NCM‐TS with a deep learning model, which allows the recognition of four types of neck motion with an average accuracy of 94%. The developed neck motion monitoring sensor has broad potential applications in sports health monitoring, rehabilitation training, and healthcare. [ABSTRACT FROM AUTHOR]

Flexible electronics show wide application prospects in electronic skin, health monitoring, and human–machine interfacing. As an essential part of flexible electronics, flexible pressure sensors have become a compelling subject of academic research. There is an urgent need to develop piezoelectric sensors with high sensitivity and stability. In this work, the high flexibility of polylactic acid (PLA) film and the excellent ferroelectric properties and high dielectric constant of tetragonal barium titanate (BTO) led to their use as filling materials to fabricate flexible piezoelectric composite films by spinning coating. PLA is used to produce flexible binding substrates, and BTO is added to the composite to enhance its electrical output by improving its piezoelectric performance. The peak output voltage of the PLA/BTO tetragonal piezoelectric film is 22.57 V, and the maximum short-circuit current was 3041 nA. Durability tests showed that during 40,000 s of continuous operation, in the range of 15~120 kPa, the linear relationship between pressure and the film was excellent, the sensitivity for the output voltage is 0.176 V/kPa, and the output current is 27.77 nA/kPa. The piezoelectric pressure sensor (PPS) also enables accurate motion detection, and the extensive capabilities of the PENG highlight its potential in advancing motion sensing and human–computer interactions.

Human skin, the body's largest organ, plays a crucial role in perceiving mechanical stimulation and facilitating interaction with the external environment. Leveraging the unique attributes of human skin, electronic skin technology aimed at replicating and surpassing the capabilities of natural skin holds significant promise across various domains, including medical care, motion tracking, and intelligent robotics. In recent research, triboelectric nanogenerators have emerged as a compelling solution for addressing the energy challenge in electronic skins. Triboelectric nanogenerators harness the combination of the triboelectric effect and electrostatic induction to efficiently convert mechanical energy into electrical power, serving as self-powered sensors for electronic skins, which possess the advantages of self-powered operation, cost-effectiveness, and compatibility with a wide range of materials. This review provides an introduction to the working principles and the four operational modes of triboelectric nanogenerators, highlighting the functional features of electronic skins, such as stretchability, self-healing, and degradability. The primary focus is on the current applications of self-powered electronic skins based on triboelectric nanogenerators in medical care, motion tracking, and machine tactile recognition. This review concludes by discussing the anticipated challenges in the future development of self-powered electronic skins based on triboelectric nanogenerators. This review holds practical significance for advancing the practical use of self-powered electronic skins based on triboelectric nanogenerators and offers valuable guidance for individuals interested in pursuing scientific and healthy endeavors. [ABSTRACT FROM AUTHOR]

The traditional motion monitoring system can only provide limited information and cannot meet people's requirements for details and accuracy. Therefore, the purpose of this paper is to develop an optical detection system based on fuzzy decision algorithm, which aims to achieve accurate and comprehensive acquisition of motion performance data and provide reliable monitoring performance in practical applications. A fuzzy decision algorithm is used to process optical signals and extract motion performance data. By establishing a suitable fuzzy rule set, the optical signal is transformed into real motion data, and the accuracy and reliability of the algorithm are verified by experiments and tests. The experimental results show that the optical detection system based on fuzzy decision algorithm can accurately collect motion performance data and has good monitoring performance. The system can maintain stable work under different lighting conditions, accurately capture and analyze the details in motion, and the system can meet people's needs for accuracy and comprehensiveness, and show good performance in practical applications. [ABSTRACT FROM AUTHOR]

Flexible sensors are becoming the focus of research because they are very vital for intelligent products, real-time data monitoring, and recording. The flat silk cocoon (FSC), as a special form of cocoon, has all the advantages of silk, which is an excellent biomass carbon-based material and a good choice for preparing flexible sensors. In this work, a flexible piezoresistive sensor was successfully prepared by encapsulating carbonized flat silk cocoons (CFSCs) using an elastic matrix polydimethylsiloxane (PDMS). The sensing performance of the material is 0.01 kPa−1, and the monitoring range can reach 680.57 kPa. It is proved that the sensor can detect human motion and has excellent durability (>800 cycles). In addition, a sensor array for a keyboard based on CFSCs was explored. The sensor has a low production cost and a simple preparation process, and it is sustainable and environmentally friendly. Thus, it may have potential applications in wearable devices and human–computer interactions. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the continuous development of flexible electronics, multi-functional device integration, artificial intelligence technology, etc., flexible wearable sensors are playing an increasingly important role in people's daily motion monitoring. However, current flexible wearable sensors have problems such as low accuracy, poor real-time performance, and poor stability in motion monitoring, which seriously hinder the better application of flexible wearable sensors and are not conducive to the collection and monitoring of motion signals. To this end, this paper designed a flexible wearable sensor motion monitoring system and tested its performance through the preparation and performance research of new functional polymer conjugated materials. The research results show that the motion monitoring system designed based on the new functional polymer conjugated material flexible wearable sensor has good monitoring accuracy and real-time performance. When the output data is 500 pieces, the running monitoring accuracy reaches 95.4%, and the monitoring feedback time is 0.321 s; the high jump movement monitoring accuracy rate reaches 97%, and the monitoring feedback time is 0.287 s; the long jump movement monitoring accuracy rate reaches 96%, and the monitoring feedback time is 0.296 s. This shows that the flexible wearable sensor motion monitoring system of this paper has better performance and can meet the current demand for accuracy and realtime motion monitoring. This study highlights the impact of new functional polymer conjugated materials on flexible wearable sensors, helping to further solve the deficiencies of flexible wearable sensors in sports monitoring and promote their better development. [ABSTRACT FROM AUTHOR]

Human physical activity monitoring plays a crucial role in promoting personalized health management. In this work, inspired by an ancient Chinese belt, a belt-type wearable sensor (BWS) based on a triboelectric nanogenerator (TENG) is presented to monitor daily movements and collect the body motion mechanical energy. The developed BWS consists of a soft silicone sheet and systematically connected sensing units made from triboelectric polymer materials including polytetrafluoroethylene (PTFE) and polyamide (PA). A parameter study of the sensing units is firstly conducted to optimize the structure of BWS. The experimental studies indicate that the parameter-optimized BWS unit achieves a maximum output voltage of 47 V and a maximum current of 0.17 μA. A BWS with five sensing units is manufactured to record body movements, and it is able to distinguish different physical activities including stillness, walking, running, jumping, normal breathing, cessation of breathing, and deep breathing. In addition, the developed BWS successfully powers electronic devices including a smartphone, digital watch, and LED lights. We hope this work provides a new strategy for the development of wearable self-powered intelligent devices.

Introduction Monitoring biomechanics is crucial in sports and rehabilitation, and frontal knee angle is of special interest in these applications. Current solutions – optical motion capture (OMC), or inertial measurement units suits – are costly, spatially constrained, and impractical for use in daily life. Textile-based wearable systems are a valuable alternative for unobtrusive movement monitoring. Textile-based wearables for knee angle monitoring have mostly been used for sagittal angle prediction, however, frontal knee angle measurement is more challenging. We investigated the design and performance of a smart garment for the detection of knee joint angles in three planes during different activities. Methods We equipped a pair of tight pants with four helical auxetic yarn capacitive strain sensors (Cuthbert et al., 2022) placed close to the knees. The exact positioning was optimized with an OMC study: markers were placed in potential sensor locations (Gholami et al., 2019) and the pairs of markers whose distance had the highest mutual information with knee angles were selected for sensor placement. A healthy participant performed walking and turning around, and knee ab/adduction activities wearing the sensorized prototype. The latter activity emphasized knee motion in the frontal and transverse planes. The capacitances from the sensors were recorded with a custom electronics board that transmitted data wirelessly to a smartphone. Multiple regression algorithms were implemented to predict knee angles from the strain sensors data, with the ground truth obtained from the OMC data recorded simultaneously during the experiments. Results The optimal sensor placements were above the kneecaps, orientated as the vastus medialis and the rectus femoris. Xgboost regression algorithm yielded best performance for walking with root mean square errors (RMSE) of 10.79°, 3.77°, and 2.49° for the sagittal, frontal, and transverse angles, respectively. Linear regression performed the best for knee ab/adduction with RMSEs of 8.96°, 6.33°, and 1.58° for the sagittal, frontal, and transverse angles (Fornaciari, 2023). Discussion/Conclusion The smart garment system was overall able to track the knee angle in three planes. The larger errors, compared with previous works (Gholami et al., 2019), reported for the walking and turning around movement are likely because of high variations in the movements of the participants during turning around. Additionally, the proposed system showed capability to monitor frontal and transverse angles with an average RMSE of 3.5°. The larger error values of the sagittal angles are likely because of higher range of motion in that plane. The proposed system allows for continuous and unobtrusive knee angle monitoring outside of the laboratory settings in the comfortable form factor of smart clothing. References Cuthbert, T. J., Hannigan, B. C., Roberjot, P., Shokurov, A. V., & Menon, C. (2022). HACS: Helical auxetic yarn capacitive strain sensors with sensitivity beyond the theoretical limit. Advanced materials, 35(10) Article 2209321. https://doi.org/10.1002/adma.202209321 Fornaciari, A. (2023). Wearable technology for lower limb movement monitoring [Master’s thesis]. Politecnico di Milano. Gholami, M., Rezaei, A., Cuthbert, T. J., Napier, C., & Menon, C. (2019). Lower body kinematics monitoring in running using fabric-based wearable sensors and deep convolutional neural networks. Sensors, 19(23), Article 5325. https://doi.org/10.3390/s19235325

With the continuous development of flexible electronics, multi-functional device integration, artificial intelligence technology, etc., flexible wearable sensors are playing an increasingly important role in people’s daily motion monitoring. However, current flexible wearable sensors have problems such as low accuracy, poor real-time performance, and poor stability in motion monitoring, which seriously hinder the better application of flexible wearable sensors and are not conducive to the collection and monitoring of motion signals. To this end, this paper designed a flexible wearable sensor motion monitoring system and tested its performance through the preparation and performance research of new functional polymer conjugated materials. The research results show that the motion monitoring system designed based on the new functional polymer conjugated material flexible wearable sensor has good monitoring accuracy and real-time performance. When the output data is 500 pieces, the running monitoring accuracy reaches 95.4%, and the monitoring feedback time is 0.321 s; the high jump movement monitoring accuracy rate reaches 97%, and the monitoring feedback time is 0.287 s; the long jump movement monitoring accuracy rate reaches 96%, and the monitoring feedback time is 0.296 s. This shows that the flexible wearable sensor motion monitoring system of this paper has better performance and can meet the current demand for accuracy and real-time motion monitoring. This study highlights the impact of new functional polymer conjugated materials on flexible wearable sensors, helping to further solve the deficiencies of flexible wearable sensors in sports monitoring and promote their better development.

Abstract Textile sensors have demonstrated significant potential in next-generation wearable systems due to their excellent performance and unobtrusive nature. By building specialized sensing networks and algorithms, textile-based wearable systems can estimate the continuous motion angles of human joints with desirable accuracies. This article offers a systematic review aimed at identifying key challenges in this field and encouraging further applications of textile strain sensor networks within the human–computer interaction (HCI) community. To achieve this, we conducted an exhaustive literature search across four major databases: IEEE Xplore, PubMed, Scopus, and Web of Science, spanning from January 2016 to August 2023. Applying inclusion and exclusion criteria, we narrowed down 2684 results to a total of 24 relevant papers. To analyze these studies, we proposed a framework that incorporates both technical aspects – such as textile strain sensors, sensor placement, algorithms, and technical evaluations – and contextual factors like target users, wearability, and application scenarios. Our analysis uncovered two critical research gaps: First, it exists an incongruity between the development of textile-based wearables and the advancements in textile sensors. Second, there is a noticeable absence of contextual design considerations in this specific domain. To address these issues, we offer discussions and recommendations from three perspectives: 1) enhancing the robustness of textile-sensing networks, 2) improving wearability, and 3) expanding application scenarios. [ABSTRACT FROM AUTHOR]

Flexible sensors, emerging as a novel sensing technology, have progressively garnered substantial interest among researchers. In recent years, there has been a growing emphasis on the utilization of nanofiber assemblies in the advancement of flexible mechanical sensors. This approach bestows upon these sensors several merits including cost-effectiveness, streamlined processing, enhanced user experience, and superior sensing capabilities. The primary objective of this review is to comprehensively assess and summarize the utilization of nanofiber sensors within the realm of flexible mechanical sensing. This endeavor aims to furnish invaluable theoretical and practical insights for the progression of flexible sensor technologies. This paper is centered on the fabrication of nanoflexible fiber sensors, primarily by methods such as polymer direct spinning, blending, nanofiber carbonization, gas phase growth, and nano-modification. Capitalizing on advancements in nanotechnology and leveraging the inherent attributes of nanofibers, and achieving breakthroughs in the development of highly sensitive, wide-range, and rapidly responsive sensors through the ingenious design of multi-tiered sensing structures, the incorporation of high-performance conductive materials, and the construction of intricate three-dimensional conductive network have garnered increasing attention from both academia and industry. Nanofiber-based mechanosensors are electronic devices utilizing flexible nanofiber aggregates as substrates. They possess the capability to detect external mechanical stimuli and convert them into electrical signals. These sensors can be categorized primarily into resistive, capacitive, piezoelectric, and triboelectric types according to their sensing mechanisms. The enhancement of nanofiber resistive flexible sensors predominantly hinges on the optimization of the sensor matrix structure and the conductive network design. Consequently, the development of resistive sensors based on nanofibers primarily revolves around refining the micro/nanostructure on the fiber’s surface and the impact of the macro-aggregate structure on resistive sensing performance. In the area of highly sensitive nanofiber capacitive mechanical sensing, the alteration of dielectric layer morphology and the reduction of compression modulus are pivotal for achieving heightened sensitivity in capacitive flexible sensors. Consequently, research in the field predominantly focuses on dielectric layer preparation. This encompasses aspects such as surface microstructures of nanofibers, composite matrices with nanofiber porosity, and textile/nanofiber composite structures. These endeavors aim to produce capacitive sensors that exhibit both high sensitivity and a broad detection range. Furthermore, to address the existing sensitivity limitations of capacitive sensors operating on the fundamental capacitance principle, there has been a recent emphasis on the concept of introducing ionic conductors into nanofibers. This approach aims to generate bilayer capacitance at the electrolyte-electrode interface, and it has garnered significant attention. In the realm of piezoelectric sensors, researchers have predominantly explored strategies to enhance the piezoelectric performance of polymer-based nanofibers. This includes avenues such as in situ polarization, nano-doping, thermal stretching, and the application of high electric fields. Within the domain of nanofiber-based triboelectric sensors, the primary focus of research centers on the inherent friction characteristics of the materials. Complementary to this, physical and chemical techniques are employed to manipulate the nanometer-scale surface morphology and facilitate surface functionalization of the materials. This, in turn, effectively enhances parameters like contact area, contact characteristics, friction effects, and ultimately augments the performance of triboelectric effect. Flexible mechanical sensors find utility across a broad spectrum of applications, spanning but not confined to domains such as health monitoring, medical diagnostics, human motion detection, and intelligent robotics. This paper undertakes a methodical endeavor to comprehensively encapsulate the multifaceted applications of nanofiber-based flexible sensors across various domains. In the domain of sports, they can be used to monitor athletes’ posture and range, analyze athletes’ movement skills and improve their performance. In the medical field, they can be used to monitor patients’ physiological parameters, such as heart rate, body temperature, blood oxygen and water equality, to realize real-time monitoring of patients’ health status, or to make intelligent medical equipment, such as intelligent artificial limbs and intelligent rehabilitation equipment, to help patients recover their functions and improve their quality of life. In the domain of intelligent robotics, flexible mechanical sensors enable interaction and perception with the environment, elevating the intelligence level of robots and empowering them to perceive user movements and sounds. Overall, the widespread application of flexible sensors significantly enhances the quality of life for individuals in diverse fields. As a vital research direction in flexible mechanical sensing, nanofiber sensors present numerous opportunities and challenges for future development. The distinctive structure and surface properties of nanofibers underpin their exceptional sensor performance, yet their mechanism of action requires further elucidation. By thoroughly exploring the interplay between nanofibers and sensor performance, sensor design and efficacy can be better optimized. Despite their commendable performance in flexible mechanical sensing, current nanofiber sensors encounter certain practical challenges, including limited sensitivity and stability. Consequently, it is imperative to conduct further research and advancements in nanofiber preparation technology to enhance the sensor’s sensitivity and stability. In conclusion, nanofiber sensors represent a promising research trajectory in the field of flexible mechanical sensing, offering vast potential for application. By refining the preparation process, delving deeper into their mechanisms, expanding their application domains, and fostering interdisciplinary collaboration, the performance and applicability of nanofiber sensors can be further enhanced. As science and technology continue to progress, nanofiber sensors are poised to yield more breakthroughs and innovations, contributing significantly to the intelligent and health-oriented development of human society. [ABSTRACT FROM AUTHOR]

Energy-autonomous wearable human activity monitoring is imperative for daily healthcare, benefiting from long-term sustainable uses. Herein, a fully self-powered wearable system, enabling real-time monitoring and assessments of human multimodal health parameters including knee joint movement, metabolic energy, locomotion speed, and skin temperature, which are fully self-powered by highly-efficient flexible thermoelectric generators (f-TEGs) is proposed and developed. The wearable system is composed of f-TEGs, fabric strain sensors, ultra-low-power edge computing, and Bluetooth. The f-TEGs worn on the leg not only harvest energy from body heat and supply power sustainably for the whole monitoring system, but also serve as zero-power motion sensors to detect limb movement and skin temperature. The fabric strain sensor made by printing PEDOT: PSS on pre-stretched nylon fiber-wrapped rubber band enables high-fidelity and ultralow-power measurements on highly-dynamic knee movements. Edge computing is elaborately designed to estimate multimodal health parameters including time-varying metabolic energy in real-time, which are wirelessly transmitted via Bluetooth. The whole monitoring system is operated automatically and intelligently, works sustainably in both static and dynamic states, and is fully self-powered by the f-TEGs. [ABSTRACT FROM AUTHOR]

The development of flexible sensors based on laser-induced graphene (LIG) has recently attracted much attention. It was commonly generated by laser-ablating commercial polyimide (PI). However, the weak mechanical extensibility of PI limits the development and diversified applications of LIG-based sensors. In this work, we adopted medical polyurethane (PU) tapes to peel off the LIG generated on PI and developed flexible and wearable sensors based on the proposed LIG/PU composite structure. Compared with other methods for LIG transfer, PU tape has many advantages, including a simplified process and being less time-consuming. We characterized the LIG samples generated under different laser powers and analyzed the property differences introduced by the transfer operation. We then studied the impact of fabrication mode on the strain sensitivity of the LIG/PU and optimized the design of a LIG/PU-based strain sensor, which possessed a gauge factor (GF) of up to 263.6 in the strain range of 75–90%. In addition, we designed a capacitive pressure sensor for tactile sensing, which is composed of two LIG/PU composite structures and a PI space layer. These LIG flexible devices can be used for human motion monitoring and tactile perception in sports events. This work provides a simple, fast, and low-cost way for the preparation of multifunctional sensor systems with good performance, which has a broad application prospect in human motion monitoring. [ABSTRACT FROM AUTHOR]

Recently, there has been remarkable progress in the development of smart textiles, especially knitted strain sensors, to achieve reliable sensor signals. Stable and reliable electro-mechanical properties of sensors are essential for using textile-based sensors in medical applications. However, the challenges associated with significant hysteresis and low gauge factor (GF) values remain for using strain sensors for motion capture. To evaluate these issues, a comprehensive investigation of the cyclic electro-mechanical properties of weft-knitted strain sensors was conducted in the present study to develop a drift-free elastic strain sensor with a robust sensor signal for motion capture for medical devices. Several variables are considered in the study, including the variation of the basic knit pattern, the incorporation of the electrically conductive yarn, and the size of the strain sensor. The effectiveness and feasibility of the developed knitted strain sensors are demonstrated through an experimental evaluation, by determining the gauge factor, its nonlinearity, hysteresis, and drift. The developed knitted piezoresistive strain sensors have a GF of 2.4, a calculated drift of 50%, 12.5% hysteresis, and 0.3% nonlinearity in parts. [ABSTRACT FROM AUTHOR]

A thin film-based strain sensor can be used for monitoring subtle and routine human activity due to its smaller dimension and portability. It could also be tailored to fit body contours. For the first time ever in this work, few-layer graphene was produced by shear exfoliation of graphite in butterfly pea extract before being layer–layer deposited as strain/acoustic sensitive coating on nylon film. The quality of the graphene produced in this study is reflected by the low defect (ID/IG: 0.25) observed under Raman spectroscopy and a C/O ratio of 4.75. The fabricated sensor can detect a wide human activity range such as eyes blinking and released/closed fist action while being equally sensitive to throat movement during drinking, laughing, nodding, and coughing besides the conventional tensile/compressive bending. The measured gauge factor is 39.37 and 21.93 for tensile and compressive, respectively, while the response and recovery time was recorded at about 1 s each. The durability of the fabricated film sensor was evidenced by the absence of mass loss despite complete immersion in water for 24 h Next, we demonstrated the potential application of this sensor for the evaluation of finger gestures during the transmission of Morse code ("dot", "dash", and "space") from the recorded electrical resistance using machine learning classification. Impressively, it was found that the performance of ML models for datasets obtained from our developed graphene/nylon sensor is tolerably above 90% overall, which strongly suggests the potential of the developed sensor as a tool for IoT or Big Data applications in the future. [ABSTRACT FROM AUTHOR]

The characteristics of real-time monitoring and flexible integration based on passive capacitive detection are becoming the preferred sensing strategy for wearable devices. However, the currently designed capacitive sensors mostly focused on the bionic microstructures to improve sensitivity and measurement accuracy, while ignoring the inherent mechanical wear and resistance of multilayer structures. In this paper, an integrated monolithic capacitive pressure detection based on room temperature liquid metal is designed and fabricated, avoiding the tightness problem of the multi-layer structure. The oxidized paste-like liquid metal owning superior interfacial wetting properties can stably adhere to the surface of the porous framework. The gas-filled porous framework endows the capacitive sensor with a mechanical response of 0.0557 g with a response and recovery time of 1.26 and 0.63 s under a load condition of 150 Pa, and steadily maintained in 1600 cycle tests. Finally, the capacitive sensor is employed to detect human physiological signals and force shock responses, which could clearly distinguish different action signals, providing a new platform for the subsequent development and design of integrated capacitive sensors. [ABSTRACT FROM AUTHOR]

Abstract Background Deep inspiration breath hold (DIBH) reduces radiotherapy cardiac dose for left-sided breast cancer patients. The primary aim of the BRAVEHeart (Breast Radiotherapy Audio Visual Enhancement for sparing the Heart) trial is to assess the accuracy and usability of a novel device, Breathe Well, for DIBH guidance for left-sided breast cancer patients. Breathe Well will be compared to an adapted widely available monitoring system, the Real-time Position Management system (RPM). Methods BRAVEHeart is a single institution prospective randomised trial of two DIBH devices. BRAVEHeart will assess the DIBH accuracy for Breathe Well and RPM during left-sided breast cancer radiotherapy. After informed consent has been obtained, 40 patients will be randomised into two equal groups, the experimental arm (Breathe Well) and the control arm (RPM with in-house modification of an added patient screen). The primary hypothesis of BRAVEHeart is that the accuracy of Breathe Well in maintaining the position of the chest during DIBH is superior to the RPM system. Accuracy will be measured by comparing chest wall motion extracted from images acquired of the treatment field during breast radiotherapy for patients treated using the Breathe Well system and those using the RPM system. Discussion The Breathe Well device uses a depth camera to monitor the chest surface while the RPM system monitors a block on the patient’s abdomen. The hypothesis of this trial is that the chest surface is a better surrogate for the internal chest wall motion used as a measure of treatment accuracy. The Breathe Well device aims to deliver an easy-to-use implementation of surface monitoring. The findings from the study will help inform the technology choice for other centres performing DIBH. Trial registration ClinicalTrials.gov NCT02881203 . Registered on 26 August 2016.

Triboelectric nanogenerators (TENGs) have recently drawn much attention in the field of biomechanical energy harvesting and motion monitoring. However, the electrode stretchability and contact-separation model induced complicated packed structure remain a problem that heavily affects output performance during various human movements and requires to be urgently addressed. Here, a single-electrode piezo-triboelectric hybrid nanogenerator (SEP-TENG) integrated with stretchable liquid-metal metal electrodes is reported, which simultaneously achieves outstanding energy harvesting performance and skin-comfort human motion monitoring. A polarized piezoelectric BaTiO3/silicon rubber (SR) composites film is served as the effective negative tribomaterial, benefiting from the improved dielectric constant and piezoelectric charge transfer, the optimized SEP-TENG generates a high peak power density of 5.7 W/m2 while contacted with human skin. Besides, owing to the ultralow Young's modulus of the SR encapsulation layer and tribo-piezoelectric hybrid layer, the homogeneous integrated multilayer composite serves no break till a 745% elongation, promoting that the SEP-TENG could effectively harvest biomechanical energy and realize stable power supplying for wearable electronics even under large deformation state. Furthermore, the SEP-TENG could comfortably attach to the finger joints and collect bending energy. This work provides a novel design methodology for a single-electrode TENG to realize omnidirectional biomechanical energy harvesting and motion monitoring.

Wearable triboelectric nanogenerators (TENGs) as self-powered sensors to monitor human motion have acquired enormous research interest owing to their low cost and highly efficient mechanical energy-harvesting property. However, development of cellulose fabric-based TENGs with excellent breathability, durability, and shape adaptivity to minimize user discomfort remains a challenge. Herein, a flexible and stretchable cotton fabric-based single-electrode-mode TENG was developed for mechanical energy harvesting and self-powered sensing to detect human motion behaviors. Breathable cotton/ammonia (95% cotton, 5% spandex) blended composite fabric was employed as flexible electrode in TENG via in situ polymerization of polypyrrole, followed by spattering of silver nanowires. Afterward, the polytetrafluoroethylene layer was coated on the surface as a tribo-negative material. The prepared TENG can maintain a stable output voltage of approximately 0.3 V under a force of 4 N at 2.5 Hz frequency. The resulting TENG also exhibited excellent air permeability of 1329.134 mm/s, moisture permeability of 399.7 g/m2·24 h, and cycle stability (above 4000 cycles) and can act as a wearable and sustainable power source for powering electronic devices. Furthermore, the cotton fabric-based TENG can be attached to the finger, wrist, or elbow as a reusable self-powered strain sensor for motion detection due to its shape adaptivity and durability. This work provides a useful design strategy for fabrication of wearable TENGs for energy harvesting and human motion monitoring. [ABSTRACT FROM AUTHOR]

High-performance flexible electronic textiles exhibit considerable potential for use as wearable energy storage and sensor fields. In this paper, we fabricated multifunctional PANI/PLA composite electronic fabrics by a simple in-situ polymerization reaction. The fabrics have an areal specific capacitance of 1171.4 mF/cm2 when used as an electrode, and the capacitance retention of 93.02% after 2000 charge/discharge cycles. The symmetric all-solid-state supercapacitors assembled based on PANI/PLA fabrics demonstrated an attractive capacitive performance with a high energy density of 30.27 μWh/cm2 at a power density of 0.217 mW/cm2. Meanwhile, the PANI/PLA electronic fabrics can also be used as flexible sensors to monitor the movement of the human body in real time. More importantly, the PANI/PLA functional fabrics also possess good flame retardant performance, antibacterial and electromagnetic shielding properties. These results indicate that the prepared PANI-coated PLA fabrics have broad application potential in wearable electronic textiles. [ABSTRACT FROM AUTHOR]

Abnormal body motion in infants may be associated with neurodevelopmental delay or critical illness. In contrast to continuous patient monitoring of the basic vitals, the body motion of infants is only determined by discrete periodic clinical observations of caregivers, leaving the infants unattended for observation for a longer time. One step to fill this gap is to introduce and compare different sensing technologies that are suitable for continuous infant body motion quantification. Therefore, we conducted this systematic review for infant body motion quantification based on the PRISMA method (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). In this systematic review, we introduce and compare several sensing technologies with motion quantification in different clinical applications. We discuss the pros and cons of each sensing technology for motion quantification. Additionally, we highlight the clinical value and prospects of infant motion monitoring. Finally, we provide suggestions with specific needs in clinical practice, which can be referred by clinical users for their implementation. Our findings suggest that motion quantification can improve the performance of vital sign monitoring, and can provide clinical value to the diagnosis of complications in infants.

Human skin, the body’s largest organ, plays a crucial role in perceiving mechanical stimulation and facilitating interaction with the external environment. Leveraging the unique attributes of human skin, electronic skin technology aimed at replicating and surpassing the capabilities of natural skin holds significant promise across various domains, including medical care, motion tracking, and intelligent robotics. In recent research, triboelectric nanogenerators have emerged as a compelling solution for addressing the energy challenge in electronic skins. Triboelectric nanogenerators harness the combination of the triboelectric effect and electrostatic induction to efficiently convert mechanical energy into electrical power, serving as self-powered sensors for electronic skins, which possess the advantages of self-powered operation, cost-effectiveness, and compatibility with a wide range of materials. This review provides an introduction to the working principles and the four operational modes of triboelectric nanogenerators, highlighting the functional features of electronic skins, such as stretchability, self-healing, and degradability. The primary focus is on the current applications of self-powered electronic skins based on triboelectric nanogenerators in medical care, motion tracking, and machine tactile recognition. This review concludes by discussing the anticipated challenges in the future development of self-powered electronic skins based on triboelectric nanogenerators. This review holds practical significance for advancing the practical use of self-powered electronic skins based on triboelectric nanogenerators and offers valuable guidance for individuals interested in pursuing scientific and healthy endeavors.

Flexible sensors are becoming the focus of research because they are very vital for intelligent products, real-time data monitoring, and recording. The flat silk cocoon (FSC), as a special form of cocoon, has all the advantages of silk, which is an excellent biomass carbon-based material and a good choice for preparing flexible sensors. In this work, a flexible piezoresistive sensor was successfully prepared by encapsulating carbonized flat silk cocoons (CFSCs) using an elastic matrix polydimethylsiloxane (PDMS). The sensing performance of the material is 0.01 kPa−1, and the monitoring range can reach 680.57 kPa. It is proved that the sensor can detect human motion and has excellent durability (>800 cycles). In addition, a sensor array for a keyboard based on CFSCs was explored. The sensor has a low production cost and a simple preparation process, and it is sustainable and environmentally friendly. Thus, it may have potential applications in wearable devices and human–computer interactions.

Background: Deep inspiration breath hold (DIBH) reduces radiotherapy cardiac dose for left-sided breast cancer patients. The primary aim of the BRAVEHeart (Breast Radiotherapy Audio Visual Enhancement for sparing the Heart) trial is to assess the accuracy and usability of a novel device, Breathe Well, for DIBH guidance for left-sided breast cancer patients. Breathe Well will be compared to an adapted widely available monitoring system, the Real-time Position Management system (RPM). Methods: BRAVEHeart is a single institution prospective randomised trial of two DIBH devices. BRAVEHeart will assess the DIBH accuracy for Breathe Well and RPM during left-sided breast cancer radiotherapy. After informed consent has been obtained, 40 patients will be randomised into two equal groups, the experimental arm (Breathe Well) and the control arm (RPM with in-house modification of an added patient screen). The primary hypothesis of BRAVEHeart is that the accuracy of Breathe Well in maintaining the position of the chest during DIBH is superior to the RPM system. Accuracy will be measured by comparing chest wall motion extracted from images acquired of the treatment field during breast radiotherapy for patients treated using the Breathe Well system and those using the RPM system. Discussion: The Breathe Well device uses a depth camera to monitor the chest surface while the RPM system monitors a block on the patient's abdomen. The hypothesis of this trial is that the chest surface is a better surrogate for the internal chest wall motion used as a measure of treatment accuracy. The Breathe Well device aims to deliver an easy-to-use implementation of surface monitoring. The findings from the study will help inform the technology choice for other centres performing DIBH. Trial registration: ClinicalTrials.govNCT02881203. Registered on 26 August 2016. [ABSTRACT FROM AUTHOR]

Given the poor mechanical properties of traditional adhesive hydrogels, many pieces of research have been focused on the preparation of adhesive hydrogels with good mechanical properties and expanded their application. In this study, a novel multifunctional adhesive hydrogel acrylated adenine/chitosan/polyacrylamide/ Fe(III)(Aa/CS/PAM/Fe(III)) hydrogels were prepared by a chemical and physical hybrid crosslinking strategy. The hydrogels can adhere to various solid substrate surfaces and show good mechanical properties. The highest adhesion strength of the hydrogel to wood reached 11.17 kPa with the fracture stress being 0.11 MPa and the toughness 0.84 MJ/m3. The hydrogels can be stretched to more than 1400% of their original length without breaking. Additionally, the hydrogels also have good repetitive adhesion and fatigue resistance. Due to the presence of Fe3+ and Cl−, hydrogels also have certain electrical conductivity, which can be used in human motion detection. [ABSTRACT FROM AUTHOR]

Simultaneously stretchable and compressible flexible strain sensors are highly desired in many advanced applications including the wearable field. However, the fabrication of such dual-function sensors with a wide sensing range is still challenging. In this work, a simultaneously stretchable and compressible foam strain sensor was fabricated by skillfully introducing oriented pores into the highly stretchable elastic composite based on carbon nanotubes and poly-(styrene-b-ethylene–butylene-b-styrene) (SEBS) by a freeze-drying method, in which cyclohexane was employed as the freeze-drying solvent. The high stretchability of SEBS and the abundant compressible space imparted by the pores endowed the resultant flexible foam sensor with highly stretchable (250%) and compressive (−50%) characteristics simultaneously. Thanks to the outstanding flexible features, the foam sensor enabled simultaneous monitoring of multiple human movements, such as bidirectional wrist bending, knee bending, foot stepping, and so forth. The foam sensor could encrypt human gesture signals into electrical signals and transmit them to the machine to realize the human–computer interaction, which could greatly broaden the application prospect of flexible strain sensors in the field of intelligent sensing. [ABSTRACT FROM AUTHOR]

As society advances, the shift from passive medical care to health management and preventive medical care has become an important issue, with the realization of wearable monitors becoming desirable. In light of the COVID‐19 pandemic, the number of patients who are in urgent need of the monitoring of biological information is increasing. This review focuses on piezoelectric materials and composites that convert kinetic energy into electrical energy to realize self‐powered wearable monitoring sensors, outlining the recent research activity on sensors for use in healthcare monitoring. First, a general description of the principles of piezoelectric monitoring sensors is given. Next, the development status of piezoelectric materials and composites aimed at the application of detecting tiny motions of the human body is introduced, and then the research trends on the detection of larger human body movements are highlighted. Finally, after presenting the performance of current piezoelectric sensors and future research guidelines for developing multifunctional systems in the post COVID‐19 era, the achievements are summarized. Overall, this review will provide guidance to researchers who are seeking to design and develop highly sensitive self‐powered piezoelectric sensors that monitor human motion and physiological signals. [ABSTRACT FROM AUTHOR]

The smart bra is a kind of sports underwear with providing health monitoring and comfort protection for women breast in sports. Developing smart sensing materials that combine comfort and functionality for sensing breast condition remains a challenge. Here, natural polysaccharide sodium alginate (SA), acrylamide (AM) monomer and chitosan (CS) and polypyrrole (PPy) in-situ polymerized from pyrole (Py) monomer were used as raw materials to successfully synthesize double network conductive hydrogel by two-step method. The results show that in the hydrogels, the entanglement and interpenetration of macromolecules produce toughness (tensile/compressive strength is ∼0.248 MPa/∼2.836 MPa), elasticity (tensile/compression elastic recovery rate is∼94.06 %/∼98.41 %) and durability (after 30 tensile/compression cycles conducting at 25 %, 50 % and 100 % constant strain keep at high recovery rate). The rich moisture content provides its adhesion (adhesion strength ∼4.7557 kPa) and flexibility (bending stiffness 1.0843 cN cm∼), presenting sufficient adhesion reliability and robustness to different substrates. The addition of PPy enables the hydrogel to have conductivity (6.77 × 10−2 S cm−1) and sensing performance (tensile/compression sensitivity is ∼1.94/∼1.43). The conductive hydrogel, as a flexible strain sensor, shows good adhesion, flexibility, elasticity and sensitivity in application of sports smart bra, can detect both the tensile behavior of skin and the compression state of tissue through its mechano-electricity, and accurately sense the changes of physiological parameters during movement. The conductive hydrogel with high elasticity and strength has broad application prospects in smart bra. [Display omitted] • A double network conductive hydrogel is successfully synthesized by two-step method. • The conductive hydrogel has excellent adhesion, softness, sensitivity and elasticity. • The hydrogel detects both skin stretching and tissue compression of women's breasts. • The hydrogel successfully senses human physiological parameters under motion state. [ABSTRACT FROM AUTHOR]

Composition and application of MPPAC hydrogels as epidermal sensors. [Display omitted] • The hydrogel multi-functional sensor showed high sensitivity and rapid response. • Conductive skin-like materials with excellent strain/pressure sensing performances. • The hydrogel is degradable and MXene can be recycled. • Machine learning module integrated to recognize human handwriting and sign language. Wearable epidermal electronics fabricated from MXene-based conductive hydrogels have attracted considerable interest because of their promising prospects in real-time health monitoring and human–computer interaction sensing. However, the development of a sustainable hydrogel with exceptional mechanical toughness, high conductivity, and self-adhesion is crucial to reliably capture signals through polymer network designs that establish robust interactions between MXene nanosheets and network substrates while minimizing electronic waste generated by discarded sensors. This study presents the fabrication of a sustainable conductive MXene-based dual-network hydrogel through skillful assembly of MXene nanosheets, β-cyclodextrin with azobenzene-modified polyacrylic acid chains, and poly (vinyl alcohol) polymer networks. The hydrogel demonstrates exceptional mechanical properties (strength at breaking ∼ 625 kPa, elongation at break ∼ 630 %) attributed to the presence of numerous hydrogen bonds and host–guest interactions, along with superior electrical conductivity (23.65 S/cm) and self-adhesion. The hydrogel demonstrates exceptional sensitivity across a wide range of strains, enabling the detection of various human movements and achieving successful applications in handwriting recognition and sign language translation. Under acidic condition and UV irradiation, the disassembly of AZO and β-CD as well as the untangling of PVA chains entanglement facilitate the release and recycling of MXene. This study presents a technological platform that holds promise for developing conductive hydrogels with enhanced sensing capabilities, catering to the requirements of stretchable electronic skin and intelligent robotic systems. [ABSTRACT FROM AUTHOR]

• The conductive silicone sponges were synthesized by the one-pot reaction within 5 min. • The sponges possessed controllable density, electrical conductivity, and excellent mechanical stability. • The sensors based on the sponges exhibited wide pressure sensing range, sensitivity and stability. • The sensors were utilized in speech recognition systems and human activity monitoring. • The sensors functioned as compressible switching devices for pressure alarms. In recent years, flexible and wearable sensors, particularly piezoresistive sensors, have been widely used in various fields such as human–computer interface, soft robotics, and artificial electronic skin. Three-dimensional (3D) conductive sponges have attracted widespread attention due to their excellent sensor performance, ease of manufacture, and seamless integration into circuits. Polydimethylsiloxane (PDMS) is widely used as an ideal substrate for these 3D conductive sponges due to its excellent chemical stability, good biocompatibility, and ideal mechanical properties. In this study, we synthesize a series of conductive silicone sponges (PCSs) by the one-pot thiol oxidative coupling reaction using commercially available multi-walled carbon nanotubes and poly((thiopropyl)methyl dimethylsiloxane). The PCSs possess controllable density and electrical conductivity. Moreover, the PCS-a sponge exhibits a wide pressure sensing range from 0.5 to 230 kPa with high-pressure sensitivity along with excellent mechanical and sensing stability. Pressure sensors fabricated using PCSs can be utilized in speech recognition systems and human activity monitoring such as arm/finger bending or walking while attached to joint positions. Additionally, they can also function as compressible switching devices for pressure alarms and LEDs. [ABSTRACT FROM AUTHOR]

We report a carbon nanotube (CNT)/Ecoflex composite strain sensor inspired by structure and function of Ruffini corpuscles, which sense skin stretch. The CNT sheet impregnated by the polymer is used as the piezoresistive material for sensing the strain, mimicking the nerve fibers generating the signal by skin stretching in the Ruffini receptor. Here, we demonstrate that the developed artificial Ruffini sensor (ARS) showed a wide working range (∼70 %), high sensitivity (GF: ∼38), high linearity at 70 % strain (R-squared: 0.967), and long-lasting durability (12,000-cycle). The insensitivity to normal pressure and wide-band frequency performances suggests that the ARS can effectively mimic those of mechanoreceptors. The sensor was affixed to areas prone to seizures in humans to measure subtle strain changes within a moderate frequency range, demonstrating the ability of the ARS to monitor rapid and minute human movements. This ARS is potentially available for the various mechano-sensing applications, including wearable robotics, and human-machine interface device that connect humans and their surrounding environments mutually. [Display omitted] • Artificial tactile sensor mimicking the structure and function of Ruffini corpuscle. • Strain sensor with high stretchability (∼70 %) and gauge factor (∼38). • Monitoring of rapid and minute human motion for seizure diagnosis. [ABSTRACT FROM AUTHOR]