Stretchable and Multimodal All Graphene Electronic Skin

Abstract

A transparent and stretchable all-graphene multifunctional electronic-skin sensor matrix is developed. Three different functional sensors are included in this matrix: humidity, thermal, and pressure sensors. These are judiciously integrated into a layer-by-layer geometry through a simple lamination process.

Nanomaterial‐Enabled Wearable Sensors for Healthcare

“…Change in humidity can affect the proton hopping and ionic conductivity of functional groups on graphene oxide, leading to increasing capacitance under higher humidity. [172] In a CNT based capacitive sensors, the presence of water vapors or other chemical solvents can enhance the fringing field of the sensor owing to the arrangement of dipoles from the water vapor or other solvents. [54] The amplitude of capacitance increase is related to the dipole moments of the solvents.…”

“…Reproduced with permission. [172] g) Schematic of a ligands functionalized AuNP sensor array for VOC detection and heart beat/breath rate sensing. Reproduced with permission.…”

“…Wearable temperature and mechanical sensors (e.g., strain sensors, pressure sensors, and force sensors) have been integrated to realize wearable health and activity monitoring, human-interactive devices and multifunctional electronic skin. [47,65,80,172,196,197] An array of temperature sensors, threeaxis tactile and slip force sensors were printed onto a flexible substrate (Figure 7d) for electronic skin, where thermoresistive CNT-PEDOT:PSS composites served as flexible temperature sensors and four resistive AgNP-CNT strain sensors were used to detect both normal pressing and slip forces. [196] Ultrathin epidermal sensors patterned in a serpentine configuration were capable of sensing both temperature and strain (Figure 7e).…”

“…[197] Thermoresistive Al 2 O 3 -doped ZnO/AgNPs temperature sensors monitored the body temperature and piezoelectric Cr/ZnO/ SWCNT sensors detected the body strain (and movement). Figure 7f presents the integration of all-graphene based sensors for transparent and stretchable electronic skin, [172] in which graphene oxide was used for capacitive humidity sensors and rGO was used for resistive temperature sensors. Cross-stacked graphene electrodes with a layer of PDMS sandwiched in between served as capacitive pressure sensors.…”

Carbon Nanofiber versus Graphene‐Based Stretchable Capacitive Touch Sensors for Artificial Electronic Skin

“…Due to their thin sheet‐like morphology, GnPs can even be molded or crumpled in situ within the embedding polymer, in such a way that under elongation they can display supercapacitance 6. Although very promising flexible capacitors have been developed with graphene or GnPs,40, 41 novel and simple GnP‐based capacitive devices that can function efficiently under 100% elongation and even more will be very beneficial for soft robotics human interactions. Similarly, buckled carbon nanotubes supercapacitors or strain sensing parallel‐plate capacitors, which function under cyclic stretching, have also been demonstrated 1, 42, 43.…”