Q Liu

High-Performance Strain Sensors with Fish-Scale-Like Graphene-Sensing Layers for Full-Range Detection of Human Motions.

Strain sensors with large stretchability, broad sensing range, and high sensitivity are highly desirable because of their potential applications in electronic skins and health monitoring systems. In this paper, we report a high-performance strain sensor with a fish-scale-like graphene-sensing layer. This strain sensor can be fabricated via stretching/releasing the composite films of reduced graphene oxide and elastic tape, making the process simple, cheap, energy-saving, and scalable. It can be used to detect both stretching and bending deformations with a wide sensing range (up to 82% strain), high sensitivity (a gauge factor of 16.2 to 150), ultralow limit of detection (<0.1% strain), and excellent reliability and stability (>5000 cycles). Therefore, it is attractive and promising for practical applications, such as for the full-range detection of human motions.

High-Quality Graphene Ribbons Prepared from Graphene Oxide Hydrogels and Their Application for Strain Sensors.

Reduced graphene oxide (rGO) ribbons with arbitrary lengths were prepared by dry spinning of the hydrogels of graphene oxide (GO) formed via thermal annealing GO dispersions, and followed by chemical reduction. These rGO ribbons are flexible, having ultrahigh tensile strengths of 582 ± 17 MPa, ultrahigh fracture energies of 18.29 ± 2.47 MJ m(-3), high conductivities of 662 ± 41 S cm(-1), and an extremely large breakdown current density of about 11,500 A cm(-2). Strain sensors based on the meshes of these ribbons showed sensitive recoverable responses to different tensile strains with excellent cycling stability, promising for the applications in wearable devices.

Transparent Polymeric Strain Sensors for Monitoring Vital Signs and Beyond

Wearable sensors that can precisely detect vital signs are highly desirable for monitoring personal health conditions and medical diagnosis. In this paper, we report an ultrasensitive strain sensor consisting of a 150 nm thick highly conductive dimethylsulfoxide-doped poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) sensing layer and an elastic fluorosilicone rubber substrate. This sensor exhibits a high sensitivity at small strains (e.g., gauge factor at 0.6% strain = 280), low limit of detection (<0.2% strain), and excellent repeatability and cycling stability. Therefore, it is promising for practically detecting vital signs, tiny human motions, and sounds. Furthermore, the semitransparent shallow blue color and the soft rubbery substrate make the strain sensor beautiful and comfortable to the human body.