Spider-Web-Inspired\nStretchable Graphene Woven Fabric for Highly Sensitive, Transparent,\nWearable Strain Sensors

Abstract

Advanced\nwearable strain sensors with high sensitivity and stretchability are\nan essential component of flexible and soft electronic devices. Conventional\nmetal- and semiconductor-based strain sensors are rigid, fragile,\nand opaque, restricting their applications in wearable electronics.\nGraphene-based percolative structures possess high flexibility and\ntransparency but lack high sensitivity and stretchability. Inspired\nby the highly flexible spider web architecture, we propose semitransparent,\nultrasensitive, and wearable strain sensors made from an elastomer-filled\ngraphene woven fabric (E-GWF) for monitoring human physiological signals.\nThe highly flexible elastomer microskeleton and the hierarchical structure\nof a graphene tube offer the strain sensor with both excellent sensing\nand switching capabilities. Two different types of E-GWF sensors,\nincluding freestanding E-GWF and E-GWF/polydimethylsiloxane (PDMS)\ncomposites, are developed. When their structure is controlled and\noptimized, the E-GWF strain sensors simultaneously exhibit extraordinary\ncharacteristics, such as a high gauge factor (70 at 10% strain, which\nascends to 282 at 20%) in respect to other semitransparent or transparent\nstrain sensors, a broad sensing range up to 30%, and excellent linearity.\nThe E-GWF/PDMS composite sensor shows a unique reversible switching\nbehavior at a high strain level of 30–50%, making it a suitable\nmaterial for fast and reversible strain switching required in many\nearly warning systems. With a view to real-world applications of these\nsensors and switches, we demonstrate human motion detection and switch\ncontrols of light-emitting-diode lamps and liquid-crystal-display\ncircuits. Their unique structure and capabilities can find a wide\nrange of practical applications, such as health monitoring, medical\ndiagnosis, early warning systems for structural failure, and wearable\ndisplays.