Bio-Inspired Hierarchical Carbon Nanotube Yarn with Ester Bond Cross-Linkages towards High Conductivity for Multifunctional Applications

The cross-linked hierarchical structure in biological systems provides insight into the development of innovative material structures. Specifically, the sarcoplasmic reticulum muscle is able to transmit electrical impulses in skeletal muscle due to its cross-linked hierarchical tubular cell structure. Inspired by the cross-linked tubular cell structure, we designed and built chemical cross-links between the carbon nanotubes within the carbon nanotube yarn (CNT yarn) structure by an esterification reaction. Consequently, compared with the pristine CNT yarn, its electrical conductivity dramatically enhanced 348%, from 557 S/cm to 1950 S/cm. Furthermore, when applied with three voltages, the electro-thermal temperature of esterified CNT yarn reached 261 °C, much higher than that of pristine CNT yarn (175 °C). In addition, the esterified CNT yarn exhibits a linear and stable piezo-resistive response, with a 158% enhanced gauge factor (the ratio of electrical resistance changing to strain change ~1.9). The superconductivity, flexibility, and stable sensitivity of the esterified flexible CNT yarn demonstrate its great potential in the applications of intelligent devices, smart clothing, or other advanced composites.

Kohti yhteiskehittelyä

Artikkelissa tarkastellaan peruskoulussa toteutettua keksintöprojektia, jonka aikana oppilasryhmä suunnitteli ja toteutti älyvaatteen. Tutkimus on osa laajempaa tutkimushanketta, jossa koulua kehitetään keksivänä ja innovatiivisena yhteisönä. Tässä tutkimuksessa selvitetään, miten oppilasryhmän älyvaatteen suunnittelu- ja valmistusprosessi eteni ja mikä rooli opettajilla oli prosessin aikana. Tutkimusaineisto sisältää yhdeksän opetuskerran videoinnit. Videoaineistoon tehdyn makroanalyysin perusteella kartoitettiin kaikki ne opetustilanteet, joissa ilmeni vuorovaikutusta opettajan ja oppilaiden välillä. Teoriaohjaavaan analyysiin pohjautuen erotellaan ja tulkitaan vuoro-vaikutuksen erilaisia muotoja. Tutkimustuloksissa korostuu opettajan rooli sekä vaatteen yhteiskehittelyssä että oppilaiden toiminnan ohjaamisessa. Yhteiskehittelyn toteutuminen edellyttää riittäviä aika- ja taitoresursseja sekä motivaatiota ratkaista haastavia suunnitteluongelmia. Towards co-creation: Observations of the teacher's role in the smart clothing project Abstract In this article we examined an invention project in a comprehensive school where a group of pupils designed and manufactured a set of smart clothing. The study is a part of a wider research project in which the school is being developed as an inventive and innovative community. In this study we analysed how the design and manufacturing processes of the smart clothing proceeded and what roles the teachers had during the process. The research data comprised video recordings of nine project sessions. All the teaching episodes containing interactions between the teacher and the pupils were surveyed as part of the macro level analysis. Based on the theory-driven analysis, the different forms of the interaction were identified and interpreted. In the results, the nature of the teacher's role emerged in both the co-creation of the smart clothing and in directing the pupils' actions. Successful co-creation requires enough time, skill, and motivation to solve challenging design problems. Keywords: discovery learning, e-textiles, apparel design, smart clothing

Validity of Trunk Acceleration Measurement With a Chest-worn Monitor for Assessment of Exercise Intensity

Background: Recent advancements in wearable technology has enabled easy measurement of daily activities, which can be applied in rehabilitation practice for the purposes such as maintaining and increasing the activity levels of the patients. A smart clothing system is one of the newly developed wearable systems that enables the measurement of physical activity such as heart rate and/or acceleration. In this study, we aimed to examine the validity of trunk acceleration measurement using a smart clothing system (‘hitoe’ system) in assessing the physical activity, which was measured using the expiratory gas analysis. Methods: Twelve healthy individuals participated in the study. The trunk acceleration was simultaneously measured using a triaxial accelerometer embedded in a smart clothing activity monitoring system (‘hitoe’ system), and the percent VO2 reserve (%VO2R) was determined by performing expiratory gas analysis during treadmill testing. Three parameters, that is, moving average (MA), moving standard deviation (MSD), and moving root mean square (RMS), were calculated using the norm of the trunk acceleration. The relationships between these accelerometer-based parameters and %VO2R from expiratory gas analysis for each individual were examined. Results: The values of MA, MSD, RMS, and %VO2R were significantly different between levels 1, 2, 3, and 4 in the Bruce protocol (P<0.01). The average coefficients of determination for individual regression for %VO2R vs. MA, %VO2R vs. MSD, and %VO2R vs. RMS were 0.89±0.05, 0.96±0.03 and 0.91±0.05, respectively. The parameters based on the trunk acceleration measurements were significantly correlated with %VO2R and activity levels. Among the parameters examined, MSD showed the best correlation with %VO2R, indicating high validity of the parameter for assessing physical activity. Conclusions: The present results support the validity of the MSD calculated from the trunk acceleration measured with a smart clothing system in assessing the exercise intensity.Trial registration: UMIN000034967Registered 21 November 2018 (retrospectively registered).

Tolerable range of abdomen and waist skin temperature for heating-capable smart garments

Purpose This study aims to provide information on how to monitor the temperature setting of a heating device in order to implement a heating unit successfully in the smart clothing by observing voluntary heating behavior of wearers.Design/methodology/approach Subjects wearing base layers and additional clothing were asked to turn on and off the switch when wanted in the cold environmental chamber. Tolerable range of skin temperature (TST) depending on the location of body was obtained by observing the temperature at the time when the heating device was turned on and off during a rest–running–rest protocol.Findings The TST was 32.8–49.4 °C and decreased to 31.3–37.6 °C around abdomen and back waist, respectively. Changes in the wearers' voluntary control behavior were observed depending on the individual's level of cold-sensitivity and activity level of rest and running. TST was 35.8–49.4 °C (Rest 1: rest before exercise), 40.0–42.0 °C (Running) and 35.3–43.2 °C (Rest 2: rest after exercise) for cold-sensitive group, whereas it was 32.8–36.2 °C (Running) and 34.4–45.7 °C (Rest 2: rest after exercise) for cold-insensitive group.Originality/value In this study, results with detailed body locations and wearer's thermal sensitivity provide practical references for the implementation of a heating device to the comfortable multilayered smart clothing.

Development of a smart clothing product using an Arduino platform

This paper presents a "smart" clothing product implemented as a jacket that contains sensors, a processing unit for display and interaction. The system has the ability to remotely read the data provided by the sensors, ensuring the monitoring of several parameters of the wearer. The following characteristics have been considered: body temperature and humidity, atmospheric temperature, pressure and altitude, the heart beat and number of steps converted into the number of calories consumed and traveled distance. The data is acquired and processed by an Arduino AT Mega 2560, via the I2C bus, digital ports and analog to digital converters, depending on the type of sensors. The processed information is printed on a 128x64 pixel display. To be able to view more pages of information, one can interact with the 4-key keyboard that has been connected to the digital input ports or through a proximity sensor, which will function as a gesture sensor. The processed information can also be accessed from a web server, built on the ESP8266 Wi-Fi module, connected to Arduino's TX/RX lines. A mobile phone or another device can connect to the Access Point and open a web page which displays the values of all sensors, as well as other information. The embedded system was inserted on a jacket and wired according to the sensors and modules usage.

Applications of Smart Clothing – a Brief Overview

Smart clothing is the next evolutionary step in wearable devices. It integrates electronics and textiles to create functional, stylish and comfortable solutions for people's daily needs. The concept includes not only clothing, which is a covering mechanism for the body but also has the function of tracking body indicators in certain situations. The review introduces the classification and concept of smart clothing, the application areas such as sports, workwear, healthcare, military and fashion. It will also outline the current state of smart clothing and the latest developments in the field, and discuss future developments and challenges.

Smart Clothing as a Noninvasive Method to Measure the Physiological Cardiac Parameters

In response to global aging, there have been improvements in healthcare, exercise therapy, health promotion, and other areas. There is a gradually increasing demand for such equipment for health purposes. The main purpose of smart clothing is to monitor the physical health status of the user and analyze the changes in physiological signals of the heart. Therefore, this study aimed to examine the factors that affect the measurement of the heart’s physiological parameters and the users’ comfort while wearing smart clothing as well as to validate the data obtained from smart clothing. This study examined the subjective feelings of users (aged 20–60 years) regarding smart clothing comfort (within 12 h); the median values were comfortable and above (3.4–4.5). The clothing was combined with elastic conductive fiber and spandex to decrease the relative movement of the fiber that acts as a sensor and increase the user’s comfort. Future studies should focus on the optimization of the data obtained using smart clothing. In addition to its use in medical care and post-reconstructive surgery, smart clothing can be used for home care of older adults and infants.