Highly flexible, durable, UV resistant, and electrically conductive graphene based TPU/textile composite sensor

Abstract

Flexible strain sensors have attracted considerable attention due to their applications in wearable monitoring fields such as human-computer interaction systems, athletic training, and health systems. Textiles are a desired substrate for fabricating wearable flexible sensors due to their light weight, comfort, and flexibility. However, the compatibility between textiles and conductive materials still faces critical challenges, especially for wearable sensors to achieve high sensitivity and a wide sensing range simultaneously with long-term monitoring stability, reliability, and wearing comfort. In this study, we propose a graphene-based TPU/textile composite sensor that can be produced using small-scale manufacturing techniques, using laser cutting combined with film coating and thermal transfer processes and further explore its mechanical, electrical, and sensing properties. Since the human body exhibits different magnitudes of motion and fabric sensors integrated into clothing would face multiple challenges in real world usage e.g. repetitive wear, sweat and sunlight exposure, we performed sensitivity, reliability and durability tests to further evaluate real world usage of the fabric sensors. The developed composite sensor exhibits a high sensitivity (GF = 498), wide sensing range (0%-293%), excellent reliability and stability which only shows 5% deviation after 10,000 cycles of stretching under 5% strain. In addition, the graphene-based textile composite sensor thermalised by TPU film can also maintain high stability after long-term UV irradiation and multiple washing cycles. When integrated into various wearable devices, our composite sensor can detect a wide range of human body motions accurately, as well as subtle physiological signals, exhibiting great potential in incorporating into wearable monitoring devices.

Embedded Pressure Sensing Metamaterials using TPU-Graphene Composites and Additive Manufacturing

“…The sensitivity of SLS-printed TPU-graphene piezoresistive compression sensors has shown in a previous study a maximum GF of -1.74 using a Schwarz structure [35]. Graphene textile piezoresistive strain sensors have reported maximum sensitivities with GF = 498 but require larger sensing ranges of 293 % [53]. The use of CNT/TPU nano-composites piezoresistive sensors has demonstrated a high linearity response with a GF = 1.42 for pressure ranges up to 40kPa [54].…”

Multifunctional flexible strain sensor based on three‐dimensional core‐shell structures of silver nanoparticles/natural rubber

“…Strain sensors typically consist of two components: an insulated stretchable matrix (e.g., polydimethylsiloxane (PDMS), 5,6 thermoplastic polyurethanes, 7,8 Ecoflex, 9 fabrics, 10 rubbers, 11 and hydrogels 12,13 ) and a highly conductive material (intrinsic conductive polymers such as polypyrrole, 14,15 polyaniline, 16,17 PEDOT: PSS, 18 metal nanoparticles like silver nanoparticles (AgNPs), 19 R 20 copper nanowires, 21 carbon-based fillers like carbon black, 22 carbon nanotubes, 1,23 reduced graphene oxide, [24][25][26] and graphene-like 2D materials like Mxene 27,28 ). AgNPs have attracted significant attention among these conductive fillers due to their various properties, including catalytic degradation of dyes, 29,30 conductivity, and antimicrobial properties.…”

Investigation of the wear and friction profile of TPU-based polymers at different infill ratios

“…TPUs have excellent elastic properties and high endurance against corrosion, humidity, and oil, and they exhibit a great absorbance capability to noise and vibrations, biocompatibility, and chemical resistance [20,21]. These superior features make popular TPUs in health care and sensor applications [22,23], automotive [24][25][26], agri-food, and military industries [21]. Recently, the demand for TPUs has increased in the industry because they are thermoplastic materials, elastomers, coatings, adhesives, or foams [27].…”