Smart Shirt for Measuring Trunk Orientation.

Improper cycling posture is linked to a variety of spinal musculoskeletal diseases, including structural malformation of the spine and back discomfort. This paper presents a novel smart shirt integrated tri-axial gyroscope and accelerometer that can detect postural variation in terms of spinal curvature changes. To provide accurate feedback to the wearer and improve the wearer's correct movement, the garment is able to recognize trunk body posture. The gyroscope/accelerometer was placed around the upper and mid trunk of the user to record tri-axial angular velocity data. The device can also be used to help determine the trunk bending angle and monitor body postures in order to improve optimal orientation and position. The garment enables continuous measurement in the field at high sample rates (50 Hz), and the sensor has a large measurement range (16 g, 2000°/s). As electronic components are non-washable, instead of encapsulating them, a detachable module was created. In this, magnets are embedded in the jersey, and allow the positioning and removal of the sensor. The test results show that the average trunk-bending angle was 21.5°, and 99 percent of the observed angle fell within the standard (ranging from 8° to 35°). The findings demonstrate the feasibility of employing the smart shirt sensor to estimate trunk motions in the field on a regular basis.

Development of Stainless Steel Yarn with Embedded Surface Mounted Light Emitting Diodes.

The integration of electronic components in/onto conductive textile yarns without compromising textile qualities such as flexibility, conformability, heat and moisture transfer, and wash resistance is essential to ensuring acceptance of electronic textiles. One solution is creating flexible and stretchable conductive yarns that contain tiny surface-mounted electronic elements embedded at the fiber level. The purpose of this work was to manufacture and subsequently evaluate the physical features and electromechanical properties of stainless steel yarn with light-emitting surface mounted devices (SMDs) embedded in it. The SMDs were successfully integrated into a conductive stainless steel yarn (SS) by inserting crimp beads and creating a bond through hot air soldering machines, resulting in what we call an E-yarn. The relationship curves between gauge length and electrical resistance, and the relationship curves between conductive yarn elongation and electrical resistance, were explored experimentally. The results of the analysis demonstrated that E-yarn had a lower tensile strength than the original electrically-conductive SS yarn. The effects of the washing cycle on the conductivity of the E-yarn were also investigated and studied. The results showed that E-yarns encapsulated at the solder pad by heat shrink tube still functioned well after ten machine wash cycles, after which they degraded greatly.

Review on the Integration of Microelectronics for E-Textile.

Modern electronic textiles are moving towards flexible wearable textiles, so-called e-textiles that have micro-electronic elements embedded onto the textile fabric that can be used for varied classes of functionalities. There are different methods of integrating rigid microelectronic components into/onto textiles for the development of smart textiles, which include, but are not limited to, physical, mechanical, and chemical approaches. The integration systems must satisfy being flexible, lightweight, stretchable, and washable to offer a superior usability, comfortability, and non-intrusiveness. Furthermore, the resulting wearable garment needs to be breathable. In this review work, three levels of integration of the microelectronics into/onto the textile structures are discussed, the textile-adapted, the textile-integrated, and the textile-based integration. The textile-integrated and the textile-adapted e-textiles have failed to efficiently meet being flexible and washable. To overcome the above problems, researchers studied the integration of microelectronics into/onto textile at fiber or yarn level applying various mechanisms. Hence, a new method of integration, textile-based, has risen to the challenge due to the flexibility and washability advantages of the ultimate product. In general, the aim of this review is to provide a complete overview of the different interconnection methods of electronic components into/onto textile substrate.

Study the Electrical Properties of Surface Mount Device Integrated Silver Coated Vectran Yarn.

Smart textiles have attracted huge attention due to their potential applications for ease of life. Recently, smart textiles have been produced by means of incorporation of electronic components onto/into conductive metallic yarns. The development, characterizations, and electro-mechanical testing of surface mounted electronic device (SMD) integrated E-yarns is still limited. There is a vulnerability to short circuits as non-filament conductive yarns have protruding fibers. It is important to determine the best construction method and study the factors that influence the textile properties of the base yarn. This paper investigated the effects of different external factors, namely, strain, solder pad size, temperature, abrasion, and washing on the electrical resistance of SMD integrated silver-coated Vectran (SCV) yarn. For this, a Vectran E-yarn was fabricated by integrating the SMD resistor into a SCV yarn by applying a vapor phase reflow soldering method. The results showed that the conductive gauge length, strain, overlap solder pad size, temperature, abrasion, and washing had a significant effect on the electrical resistance property of the SCV E-yarn. In addition, based on the experiment, the E-yarn made from SCV conductive thread and 68 Ω SMD resistor had the maximum electrical resistance and power of 72.16 Ω and 0.29 W per 0.31 m length. Therefore, the structure of this E-yarn is also expected to bring great benefits to manufacturing wearable conductive tracks and sensors.