Wear Comfort Research Articles

Eco-friendly and controlled anti-pilling finishing of wool fabric by thiourea dioxide-mediated surface micro-dissolution

PurposeWool, mainly composed of keratin, is a relatively high-grade clothing material. Although woollen textile has the advantages of high wearing comfort and excellent warmth retention property as we have known, its inherent disadvantage of easy pilling has easy puzzled people for a long time. Most of the existing technologies for pilling resistance are not eco-friendly or severely damaged the internal structure of wool.Design/methodology/approachIn this work, a controlled and effective surface treatment method was proposed to controllable micro-dissolution the scale layers of wool with minor damage to its internal structure, thereby improving the anti-pilling property of wool. Thiourea dioxide (TD) is used as a dissolving agent to swell and dissolve wool surface flakes. After TD treatment, the morphology changes of wool fibers were observed by scanning electron microscope (SEM) and methylene blue staining. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were used to characterize the structural changes of TD wool. At the same time, the anti-pilling properties and wettability of wool fabrics were tested.FindingsThe results show that the wool scale layer is destroyed after TD treatment, which reduces the friction between fibers and improves the anti-pilling performance of wool fabrics. The methylene blue-stained images further demonstrate that low concentrations of TD can damage the superficial scale layer of wool without significant loss of strength.Originality/valueThis method is simple, eco-friendly and economical, and opens up a new direction for the surface treatment of wool fabrics.

Fabrication of air‐conditioning tussah silk with capric–stearic eutectic mixture for effective energy storage and thermal‐regulatory applications

AbstractUnder the urgent demand of effective energy‐storage and thermal‐regulatory textile fabrics, the air‐conditioning tussah silk as a new arrival is endowed with this excellent property by coupling with the phase change material of capric acid–stearic acid eutectic mixture. In addition, the facile pad‐dry‐cure technique used with the assistance of ultrasonic waves efficiently avoided the problems of the sophisticated process and low efficiency in traditional post‐finishing methods with phase change microcapsules. With optimal preparation conditions, the resultant tussah silk exhibited a superior thermal reliability and thermoregulatory character along with a phase enthalpy of 31.80 J g−1 at a phase change temperature of 24.01 °C. Meanwhile, the tested air permeability, mechanical properties and washing fastness showed its favorable thermal and wear comfort. Benefitting from these admirable merits, this air‐conditioning tussah silk with tunable heat storage and release performance could automatically respond to external temperature stimuli, finally contributing to practical application in intelligent protective garments. The intelligent bidirectional temperature‐adjusting property corresponding to the efficient management of human skin temperature is beneficial for constructing a comfortable microclimate for the human body. In brief, our study provides a novel heat‐storage and temperature‐regulating textile with tussah silk as well as unique natural advantages by means of a simple preparation method. © 2022 Society of Industrial Chemistry.

Preliminary clinical effect evaluation of digital head and neck radiotherapy oral positioning stents

Objective: To develop a designing software of digital oral positioning stent for radiotherapy of head and neck, and to compare its clinical effect with traditional oral positioning stents made by lost wax process. Methods: Thirty patients with nasopharyngeal cancer who received oral examination before radiotherapy in the prosthodontics department from July to December, 2021, were selected and divided into three groups according to the patients' wishes, 10 per group: one group without radiotherapy oral positioning stents, one group with traditional oral positioning stents (traditional stents group), and the third group with digital oral positioning stents (digital stents group). Patients' ages range from 20 years old to 71 years old. There were 15 males and 15 females involved in this study. The manufacturing time and comfort of the two positioning stents were evaluated, and the radiation doses of the radiotherapy target areas and surrounding healthy tissues were statistically analyzed at the end of radiotherapy. Results: The manufacturing time of digital stents group [(209±7) min] was much less than that of traditional stents group [(490±10) min] (t=69.85, P<0.001). The comfort of patients' wearing of digital stents [first wearing: 5 (3, 6) score; at the end of radiotherapy: 4 (3, 5) score] was better than that of traditional ones [first wearing: 7 (3, 7) score; at the end of radiotherapy: 7 (3, 7) score] (U=22.00, P=0.033; U=20.50, P=0.023). There was no significant differences in the target radiation doses among the three groups, and the radiation doses of tongue [traditional stents group: (36.74±5.45) Gy; digital stents group: (35.96±4.98) Gy] and mandible [traditional stents group: (35.46±4.19) Gy; digital stents group: (35.34±3.98) Gy] were significantly lower in the patients wearing oral positioning stents than in the patients without oral positioning stents [tongue: (41.49±4.46) Gy; madible: (39.32±3.52) Gy] (P<0.05). Conclusions: Oral positioning stents for nasopharyngeal carcinoma radiotherapy could greatly reduce the exposure doses of tongue and madible of patients. Digital oral positioning stents designed and manufactured by independently developed software had higher production efficiency than the traditional method, and patients' evaluation of comfort was better.

Sacrificial Template Method to Fabricate Highly Sensitive Porous Capacitive Pressure Sensor for Full Pulse Waveform Detection

Due to the recent advancements in sensing technology, skin mountable wearable devices have gained much attention due to their non-invasive usage and wearer comfort for health care monitoring. For instance, monitoring pulse waveform from the wrist arterial sites bears tremendous information about cardiovascular health and can show abnormalities such as hypertension or arterial fibrosis. Acquiring a high-quality pulse waveform from the wrist artery requires high-pressure sensitivity and fast response time. However, the need for building highly sensitive and low-cost fabrication of the sensors for subtle physiological monitoring is still challenging. Targeting these issues, this study presents a facile and cost-effective approach to realizing a flexible capacitive pressure sensor by sandwiching porous polydimethylsiloxane (PDMS) polymer functionalized by multi-walled carbon nanotubes (MWCNTs) fabricated by sacrificial template method for physiological monitoring. The fabrication steps for the dielectric layer involve mixing sucrose as the porogens and MWCNTs as the functionalizing material with PDMS followed by casting the mixture in a mold and curing of the PDMS. Subsequently, the sucrose particles are dissolved in water. The sucrose particles are easily dissolved in water leaving a highly uniform and porous structure behind. The dielectric layer is then sandwiched between two conductive textile based electrodes for physiological monitoring. The electromechanical tests were performed for different concentration of MWCNTs content in porous PDMS to obtain the best sensing performance. The champion sensor exhibits ultrahigh-pressure sensitivity of 2.41kPa-1 and a minimum detection limit of 1.4Pa in contrast to the sensor exhibiting only 0.31kPa-1 without addition of any MWCNTs. In addition, the pressure sensor shows a fast response time of 0.18s and excellent cyclic stability over 6000 cycles. The ultrahigh-pressure sensitivity comes from the addition of conductive MWCNTs filler that increases the dielectric permittivity. The highly porous structure of the polymer reduces the typical viscoelastic effects of polymer resulting in fast response time. The pressure sensor could detect arterial pulse waveform from the wrist artery with all the key characteristic points showing its promises for low-cost physiological monitoring. The detailed results will be discussed during the presentation.

Artificial intelligence‐enhanced skin‐like sensors based on flexible nanogenerators

AbstractArtificial intelligence‐enhanced skin‐like sensors based on flexible nanogenerators have been widely used in physiological signal acquisition, artificial organ, sensory simulation, human movement status recognition, and other biomedical related fields due to their excellent biocompatibility, comfortable wearing experience, high sensing accuracy, and low power consumption. In this paper, the working principle, evolution process, and several established general strategies of artificial intelligence‐enhanced skin‐like sensors are summarized in detail. More importantly, this paper further reviews several recent important advances on artificial intelligence enhanced skin‐like sensor, and systematically analyzes and compares these works according to their principles and application directions. In the discussion section, we also list the current concerns of stress adaptation, stretchability–conductivity, algorithm optimization, function integration, and propose potential solutions to these problems. We hope that the deep integration of artificial intelligence and flexible nanogenerators can bring more enlightenment to the progress of biomedical engineering in the future.

Breathable fabric-based triboelectric nanogenerators with open-porous architected polydimethylsiloxane coating for wearable applications

Triboelectric nanogenerators (TENGs), which can harvest low-frequency mechanical energy from human activities, are potential for wearable electronics, especially textile-based TENGs. Besides triboelectric performance, wearable comfort, like air permeability, is crucial for wearable electronics. However, the textile-based TENGs integrated with high performance and wearable comfort still remain challenging. Here, we construct the open porous architected PDMS coatings on fabric for breathable fabric-based TENG (oPF-TENG) based on the synergistic effect of insoluble NaCl, DBP and soluble silicone oil. The open porous structure constitutes the airflow channel with the air permeability of ∼73 mm/s. Meanwhile, the porous structure and the PVDF filler enhance the triboelectric output. The open circuit voltage, short circuit current and power density of oPF-TENG reach ∼600 V, ∼15 μA and 5.67 W/m2, respectively. The as-made oPF-TENG with good air permeability and triboelectric output can not only contribute to the human body energy harvesting but also show potential for wearable self-powered sensing.

An Assistive Explicit Model Predictive Control Framework for a Knee Rehabilitation Exoskeleton

This article focuses on the control of an actuated knee joint orthosis. The proposed solution is a novel model predictive control framework dedicated to assistive and rehabilitation purposes. This framework includes 1) an exact input-to-state feedback linearization, 2) a model predictive controller (MPC or EMPC), considering input/output constraints, 3) a least-squares dynamic parameters identification, 4) a nonlinear disturbance observer for the estimation of the wearer’s torque, 5) a Lyapunov-based stability analysis of the resulting closed-loop system, and 6) a reference trajectory generator. The proposed framework has been validated via real-time experiments performed on three healthy subjects wearing the knee joint orthosis. Various experimental scenarios have been considered, including assistive and resistive rehabilitation tasks in a sitting position and walking with normal/abnormal gait patterns. The obtained results indicate the efficiency of the proposed predictive controllers with respect to a conventional proportional-integral-derivative (PID) controller in terms of tracking performance, required torque, and wearer comfort.

A Wearable Electrocardiography Armband Resilient Against Artifacts

Electrocardiography (ECG) is an essential technique to assess cardiovascular conditions and monitor physical activities. While the concept is mature, issues surrounding sampling convenience and device adoption as well as maintaining signal quality under artifacts remain a problem. In this article, we present a high-performing wearable ECG armband on the upper left arm. It is equipped with miniaturized hardware, capable of data storage and wireless communication. We evaluate different electrode configurations by conducting ECG measurements both at the static state and under motion and using improved algorithms to quantify data quality and assess the agreement between the proposed new technique and the gold standard. The optimal electrode position is determined by balancing wearable suitability and signal quality. We propose an electronic textile (E-textile) armband with improved design. It offers favorable wearing comfort and a fashionable appearance without sacrificing data quality. Its contact pressure is measured to get a better picture of intimacy and clothing comfort. Our system provides real-time and noise-resilient ECG data without interrupting daily life and can be implemented in use cases that warrant continuous ECG monitoring.

Hierarchically Designed Super‐Elastic Metafabric for Thermal‐Wet Comfortable and Antibacterial Epidermal Electrode

AbstractOn‐skin electronic systems represent a burgeoning technology that develops wearable devices capable of adapting to the dynamic surfaces of the human body. Present film‐based electronics are constrained to single‐layered constructions on impermeable substrates that severely inhibit their wearing comfort and multi‐functionality. Herein, a thermal‐wet comfortable and antibacterial epidermal electrode is hierarchically designed on an ultra‐stretchable metafabric. Via the layer‐by‐layer assembly of trilayered elastomeric fibers with multi‐scale sizes and varied compositions, porosity and wettability asymmetries are established across the nonwoven fabric, rendering it with unidirectional liquid conduction and sweat self‐pumping performance. The successful printing of stretchable liquid‐metal (EGaIn) circuits on ZnO NPs anchored microfibers simultaneously equips the trilayered metafabric with robust antibacterial capability, low‐watt heating ability, and high‐fidelity detectability for surface electromyography signals of various physical activities. Moreover, the incorporation of thermochromic microcapsules in the outmost fibers also enables the fabric Joule heater with visual indicating ability via reversible color‐switching. Thus, this hierarchically engineered epidermal electrode with thermal‐wet comfort and antibacterial ability holds great promise in daily applicable healthcare and sports monitoring electronics.

A new thermal protective clothing design with silica aerogel filled acrylic nanofibers

PurposeFirefighters are exposed to high outdoor temperature and heat stress caused by metabolic activities during firefighting and should wear protective clothing to ensure their safety and health. Traditional firefighter protective suits are bulky and heavy garments with reduced thermal comfort properties since the fabric thickness and moisture barrier layers prevent heat transfer of the garment and cause additional heat stress. The aim of this study is to reduce heat stress by creating a new fabric design with silica aerogel membrane as a moisture barrier for three-layer fabric system.Design/methodology/approachPolyacrylonitrile (PAN) nanofibers were produced with three different silica aerogel contents and used for three-layered clothing system as a moisture barrier for giving desired protectiveness and thermal comfort to firefighters. Different fabric combinations were designed using two types of outer shell fabrics, two types of moisture barrier fabrics, two types of thermal barrier fabrics and PAN/silica aerogel membranes.FindingsThe results show that a lighter fabric system with improved wearer’s mobility and thermal comfort properties (thermal resistance and moisture permeability) is achieved with the use of PAN/silica aerogel membrane as an intermediate layer compared to commercial thermal protective fabric systems.Originality/valueDifferently from traditional thermal protective clothing, which may not provide adequate protection in long-term heat conditions or when exposed to flash fire, a new thermal protective clothing has been developed to be used in extremely hot environments, providing desired technical and performance properties, ease to wear comfort.

Soft-covered wearable thermoelectric device for body heat harvesting and on-skin cooling

The recent emergence of self-powered wearable electronics gives rise to a growing demand for flexible, sustainable, and portable power supply. Wearable thermoelectric devices (WTEDs) are promising power sources for wearable electronics through directly converting body heat into electricity. However, the output power of WTEDs is still low due to the extremely small effective temperature difference across thermoelectric pillars, which hinders their practical applications. Commonly used strategies to enlarge the effective temperature difference for WTEDs, such as introducing metallic heat sinks or increasing the length of thermoelectric pillars, usually lead to clunky devices that are not suitable for wearable electronics. Here, we report on a soft-covered WTED for body heat harvesting and on-skin cooling, which demonstrates the desirable performance and wearer comfort. Distinct from the previously reported flat soft heat spreaders, this work presents the design and fabrication of a pin–fin soft cover that can serve as a flexible heat sink for WTEDs. The pin–fin soft cover was fabricated by curing the liquid metal/elastomer composite in a meltable wax mold. Systematic theoretical and finite element analysis was conducted to optimize the output power and wearability of the soft-covered WTED. The optimized WTED achieves a power density of 6.63 μW cm−2 on a stationary human body under natural convection condition with an ambient temperature of 20 °C, which is higher than the previously reported WTEDs with flat soft covers made of high-thermal-conductivity elastomers. Furthermore, our WTED can realize a 1.5 °C temperature drop for the human skin through Peltier cooling. This work demonstrates a new route to develop soft-covered WTEDs for self-powered wearable electronics and personal thermoregulation.

A reliable method by utilizing thermo-responsive palladium nanocomposite for fabricating Nickel coating on nylon 6 fabrics

Flexible conductive textiles are one of the best choices for smart textiles due to their comfortable wearing and good compliance with the human body. The great adhesion and durability of metal coatings onto substrate surfaces are important indicators for the high-performance requirements of smart textiles. The main bottleneck for the development of flexible conductive textiles is the poor adhesion between the metal coating and the substrate, so efforts have been made to improve it on a variety of fabrics. Herein, we reported a facile and economical method to fabricate flexible conductive fabrics using commercial nylon 6 fabrics as substrates. In brief, Styrene-co-N-Isopropylacrylamide/Pd (St-co-NIPAAm/Pd) nanocomposites acted as activators and adhesive interlayers for electroless plating to improve the adhesion of the nickel layer onto the nylon 6 surface. A highly conductive nylon 6 fabric was prepared by a coating of St-co-NIPAAm/Pd nanocomposite and followed by Ni-P electroless plating. The optimal electroless plating process parameters for fabricating adhesion-enhanced and highly reliable nickel coating were also investigated in the study. Its reliable conductivity and high durability mean it is promising for smart textiles, even via a series of repeated bending and washing tests. In addition, we explain the mechanism by which St-co-NIPAAm/Pd nanocomposites change at a temperature below or beyond the lower critical solution temperature (LCST). To sum up, the developed conductive nylon 6 fabric can lay the groundwork for the subsequent development of smart textiles.

Perspiration-Wicking and Luminescent On-Skin Electronics Based on Ultrastretchable Janus E-Textiles

Stretchable electronics have attracted surging attention for next-generation smart wearables, yet traditional flexible devices fabricated on hermetical elastic substrates cannot satisfy lengthy wearing comfort and signal stability due to their poor moisture and air permeability. Herein, perspiration-wicking and luminescent on-skin electrodes are fabricated on superelastic nonwoven textiles with a Janus configuration. Through the electrospin-assisted face-to-face assembly of all-SEBS microfibers with differentiated diameters and composition, porosity and wettability asymmetry are constructed across the textile, endowing it with antigravity water transport capability for continuous sweat release. Also, the phosphor particles evenly encapsulated in the elastic fibers empower the Janus textile with stable light-emitting capability under extreme stretching in a dark environment. Additionally, the precise printing of highly conductive liquid metal (LM) circuits onto the matrix not only equips the electronic textile with broad detectability for various biophysical and electrophysiological signals but also enables successful implementation of human-machine interface (HMIs) to control a mechanical claw.

A nano-micro structure engendered abrasion resistant, superhydrophobic, wearable triboelectric yarn for self-powered sensing

Smart wearable electronics with harvest energy are rapidly developing in modern life. Fiber-based triboelectric generators (TENGs) are gaining extensive attention for energy harvesting and human motion sensing, due to flexible, lightweight, and comfortable properties. However, it is difficult to coordinate the high electrical output performance of fiber-based TENGs with the requirements of human wearing comfort (abrasion resistant, air permeability and skin-friendliness). Herein, a novel nano-micro structure yarn (NMSY) with three layers was proposed via combining conjugated electrospinning as well as ring spinning together. Therein, electrospinning Nylon 11 nanofibers were applied as the intermediate layer to enhance electrical output performance and ring spinning polyester fibers wrapped as the outermost layer to improve abrasion resistance. The obtained NMSY exhibits high output voltage (17.5 V in 3.5 cm) and wear resistance (4500 abrasion cycles). Furthermore, an electronic textile (e-textile) was knitted with NMSY (2.5 × 2.5 cm2), which exhibited a power density of 487.8 mW/m2 at a load resistance of 700 MΩ. Owing to the unique interconnected loop structure of knitted textiles, NMSY e-textile shows good air permeability (147.3 mm/s), water vapor transmission rate (3470 g/(m2·24h)) and excellent skin-friendly. In practical application, NMSY e-textile can lit up 22 LEDs and also can charge the commercial capacitors efficiently. Besides, NMSY as well as the corresponding e-textile can also be used as self-powered sensors to monitor body movement. In summary, the superior NMSY presented in this work could enhance energy harvest and wearability, which would pave the way toward full-fledged commercialization of the TENGs in the future.

Flexible, stretchable, breathable and sweatproof all-nanofiber iontronic tactile sensor for continuous and comfortable knee joint motion monitoring

Running improperly for an extended period of time will induce irreversible damage to knee joints, which can bring about excruciating pains to joggers. Wearable sensors for continual knee-monitoring are highly recommended. However, conventional flexible sensors built on airtight substrates are inferior in comfort when wearing for lengthy durations. Herein, a highly flexible and stretchable iontronic tactile sensor is developed on an electrospun thermoplastic polyurethane nanofiber platform. The multilayered, intertwined, nanofiber network housing numerous micro-pores/channels endows the sensor with superior air permeability, sweat inertness, thermal dissipation ability, and biocompatibility, which allows for an extended, comfortable wearing experience. Accrediting the supercapacitive sensing mechanism and porous microstructure, a performance exhibiting a high sensitivity, wide detection range, rapid response, excellent stability and repeatability can be achieved. Pragmatically, a knee-sensor prototype was developed and demonstrated running in real-time and continuously: monitoring a single point of pressure with 3 individual sensor units attached to the rim of the knee and mapping the spatial pressure distribution with an array of sensors covering the whole knee. The health status of the knee could be properly diagnosed, which would be useful for warning of potential knee injuries or to better the form of exercisers.

Laser‐induced graphene‐based flexible interdigital electrode realizing micro supercapacitor sustainable in different temperatures

AbstractElectronic components for energy storage need to be mechanically conformable to ensure maximum wearer comfort, flexibility, and good thermal stability in different environments. Hence, the development of supercapacitors (SCs) as an alternative to micro‐batteries for use in microelectronics applications is currently receiving much scientific attention. This work presents an adaptable, cost‐effective, and efficient method to fabricate flexible laser‐induced graphene (LIG) supercapacitor electrodes using a CO2 laser. LIG formation and morphology have been studied and confirmed through energy dispersive X‐ray (EDX) spectroscopy and scanning electron microscopy (SEM) techniques. The interdigital laser‐induced graphene electrodes are fabricated and optimized for SCs on a flexible substrate. These SCs have the advantages of charge‐discharge cycles, capacitive performance, high power density as well as long cyclic life. For LIG electrodes, the suitable electrolyte is optimized to control the electrochemical properties of supercapacitors, such as charge transfer, flexibility, and stability. Hence, a supercapacitor composed of 3D porous laser‐induced graphene with PVA‐KOH gel electrolyte is fabricated, with 83.33 mF/cm2 areal capacitance at a constant current density of 0.5 mA/cm2. The energy density 4.62 μWh/cm2 and power density 0.2 mW/cm2 are observed at a 0.5 mA/cm2 constant current density. The capacitance of the proposed SC increases with an increase in certain temperatures and shows excellent performance. This flexible SC could be a high potential for use in energy storage and wearable device applications.

Influence of Upper Footwear Material Properties on Foot Skin Temperature, Humidity and Perceived Comfort of Older Individuals.

Studying the in-shoe microclimate of older individuals is important for enhancing their foot comfort and preventing foot diseases. However, there is a lack of scientific work that explores the thermo-physiological wear comfort of older individuals with different footwear. This study aims to examine the effects of upper footwear materials on changes and distributions in the foot skin temperature and relative humidity for older individuals. Forty older individuals are recruited to perform sitting and walking activities under four experimental conditions in a conditioning chamber. The findings indicate that footwear upper constructed of highly permeable mesh fabric with large air holes shows fewer changes in foot skin temperature (ranging from 1.3 to 3.3 °C) and relative humidity (ranging from −13.3 to 5.7%) throughout the entire foot during dynamic walking, as well as higher subjective ratings on perceived thermal comfort when compared to footwear made of synthetic leather and composite layers. The findings serve to enhance current understanding of designing footwear with optimum comfort for older adults.

Evaluation of Signal Quality from a Wearable Phonocardiogram (PCG) Device and Personalized Calibration

Currently, the only clinically utilized Phonocardiogram (PCG) is an electronic stethoscope used in a hospital or clinical environment. The availability of continuously recorded PCGs can provide a new avenue of research into chronic disease management at home. Researchers have proposed such wearable PCG devices. However, limitations exist in evaluating such devices as PCG recording devices in home-like environments. Here, we evaluate a wearable PCG system in a belt-type form factor with an embedded force sensor, accelerometer, and a single lead ECG to study the feasibility of acquiring diagnostic-grade PCGs while the wearer performs daily activities. We describe qualitative and quantitative exploratory analysis methods for cross-subject comparison of PCG signal quality, wearer comfort, and the impact of activities using Signal-to-Noise (SNR) comparisons and cross-spectral coherence between activity and PCG. The analysis of the data suggests that a common user-chosen method of donning a wearable PCG is not applicable across subjects for obtaining optimal PCG recording quality. We propose a method to calibrate wearable PCG devices using an embedded force sensor and by following a protocol involving feedback from the embedded force sensor to determine the optimal method of wearing the device. Following a similar path to precision medicine using genomic data and the extrapolation of risk, wearable devices with healthcare applications should be developed with the ability to be adapted and calibrated to each individual. In the immediate future this may involve calibration procedures such as those followed in this work, using controlled measurements performed with each patient to tune a device for them.

Directional sweat transport window based on hydrophobic/hydrophilic Janus fabric enables continuous transfer and monitoring of sweat

Wearable sweat sensors are promising for non-invasive and real-time health monitoring but still confront notable challenges, such as the inaccuracy caused by sweat accumulation/evaporation in sensing area and the wear discomfort due to accumulated sweat and lack of breathability. In this work, we present an all-fabric-based sweat sensing platform based on a novel design of directional sweat transport window for continuous transfer and monitoring of sweat. The directional sweat transport window is built based on hydrophobic/hydrophilic Janus wettability on fabric's two sides, integrated in a highly hydrophobic cotton fabric, and sandwiched between hydrophilic cotton layers. Through the window, sweat collected by inner cotton layer from area in and around the window can be directionally and spontaneously transferred from hydrophobic side to hydrophilic side, even when the hydrophobic side faces downward, i.e., irrespective of gravity. The outer cotton layer serves to draw sweat away from hydrophilic side of directional sweat transport window through continuous evaporation, and thus also as reservoir for sweat residue. Fiber-shaped sensing electrodes were fixed on the hydrophobic side of directional sweat transport window. The directional sweat transport function reduces the time that the sweat remains in the sensing area, thus effectively avoiding the sweat accumulation and enhancing the sensing stability and accuracy, as well as the wear comfort. As a proof of concept, we demonstrated on-body, wireless monitoring of the sweat of a volunteer in physical exercise. Such a directional sweat transport window strategy also shows potential as a platform technology for other wearable applications.

Long-Term Device Satisfaction and Safety after Cochlear Implantation in Children.

(1) Objectives: For full benefit in children implanted with a cochlear implant (CI), wearing the device all waking hours is necessary. This study focuses on the relationship between daily use and audiological outcomes, with the hypothesis that frequent daily device use coincides with high device satisfaction resulting in better functional gain (FG). Confounding factors such as implantation age, device experience and type of device were considered. (2) Results: Thirty-eight CI children (65 ears) were investigated. In total, 76.92% of the children were using their device for >12 h per day (h/d), 18.46% for 9–12 h/d, the remaining for 6–9 h/d and one subject reported 3 h/d. The revision rate up to the 90-month follow-up (F/U) was 4.6%. The mean FG was 59.00 ± 7.67 dB. The Audio Processor Satisfaction Questionnaire (APSQ) separated for single unit (SU) versus behind the ear (BTE) devices showed significantly better results for the latter in terms of wearing comfort (WC) (p = 0.00062). A correlation between device use and FG was found with a device experience of <2 years (n = 29; r2 = 0.398), whereas no correlation was seen with ≥2 years of device experience (n = 36; r2 = 0.0038). (3) Conclusion: This study found significant relationships between daily device use and FG, wearing comfort and long-term safety (90 months).