High Durability and Waterproofing rGO/SWCNT-Fabric-Based Multifunctional Sensors for Human-Motion Detection

Abstract

Wearable strain-pressure sensors for detecting electrical signals generated by human activities are being widely investigated because of their diverse potential applications, from observing human motion to health monitoring. In this study, we fabricated reduced graphene oxide (rGO)/single-wall carbon nanotube (SWCNT) hybrid fabric-based strain-pressure sensors using a simple solution process. The structural and chemical properties of the rGO/SWCNT fabrics were characterized using scanning electron microscopy (SEM), Raman, and X-ray photoelectron spectroscopy (XPS). Complex networks containing rGO and SWCNTs were homogeneously formed on the cotton fabric. The sensing performance of the devices was evaluated by measuring the effects of bending strain and pressure. When the CNT content was increased, the change in relative resistance decreased, while durability was significantly improved. The rGO/SWCNT (0.04 wt %) fabric sensor showed particularly high mechanical stability and flexibility during 100 000 bending tests at the extremely small bending radius of 3.5 mm (11.6% bending strain). Moreover, the rGO/SWCNT fabric device exhibited excellent water resistant properties after 10 washing tests due to its hydrophobic nature. Finally, we demonstrated a fabric-sensor-based motion glove and confirmed its practical applicability.

Significance of Nanomaterials in Wearables: A Review on Wearable Actuators and Sensors

“…[162][163][164][165] To date, many research reports have started to develop multifunctional wearable sensors for tracking human motions by real-time continuous signals. Simultaneous differentiation is also a required functionality together with the integrated diversity among different stimuli like strain, twist, temperature, light, humidity, and the environmental gasses.…”

Graphene‐Coated Spandex Sensors Embedded into Silicone Sheath for Composites Health Monitoring and Wearable Applications

“…In particular, this issue is of significance when it comes to wearable sensors wherein the sensor may undergo a wide range of strains as tiny as heart beat to rigorous joint motions . Besides, piezoresistive sensors are highly prone to performance degradation upon exposure to quantities such as high humidity and temperature, and hence there is an urgent need to obviate sensor cross‐sensitivity and vulnerability to harsh environments . This is a serious issue for wearable sensors where wash durability and thereby appropriate protection is needed for the sensors.…”

Flexible Multifunctional Sensors for Wearable and Robotic Applications

“…The GSMN fiber can stretch up to 400% and this high elasticity and elongation can be attributed to the unique spring-like mesh network. The laundering durability of fabrics has been explored in some studies either by using a standard washing launder machine, [139] vigorously stirring in water, [29,142] or using a standard detergent according to the ISO 105/C01. The GSMN, when acting as a pressure sensor, exhibited a high sensitivity of 72 kPa −1 , see Figure 9c, and could detect a low pressure of 1.38 Pa induced by a drop of water.…”

“…The GSMN, when acting as a pressure sensor, exhibited a high sensitivity of 72 kPa −1 , see Figure 9c, and could detect a low pressure of 1.38 Pa induced by a drop of water. Kim et al [142] developed a high durability and waterproofing conductive fabric glove to detect human motion. [127] Other carbon-based materials can be introduced to enhance the performance of graphene.…”

“…It could be further attached www.advmattechnol.de on the human body for physiological signal monitoring, such as pulse recording, as shown in Figure 9c. [142] However, there are some conductive fabrics that cannot survive the laundering test at high temperature. A sandwich-structured conductive natural wool can simultaneously function as a wearable, stretchable, and sensitive strain sensor and also as a wearable heater by immersing natural wool in hybridized graphene nanoplatelets (GNPs) and carbon black (CB) particles mixture suspension.…”