Three-Dimensional Binary-Conductive-Network Silver Nanowires@Thiolated Graphene Foam-Based Room-Temperature Self-Healable Strain Sensor for Human Motion Detection

Abstract

A lot of attention has recently been focused on wearable strain sensors because of their promising applications in the rising areas of human motion detection, health monitoring, and smart human−machine interaction. However, the design and fabrication of self-healable strain sensors with superior overall properties including stretchability, sensitivity, response ability, stability, and durability is still a huge challenge. Herein, we report an innovative self-healable strain sensor with exceptional overall performance constructed with three-dimensional binary-conductive-network silver nanowire-coated thiolated graphene foam (AgNWs@TGF) and room-temperature self-healing functionalized polyurethane (FPU) elastomer. Taking advantage of the good ductility and continuity of the AgNWs@TGF binary structure and the excellent resilience of the FPU, the strain sensor exhibits good stretchability (up to 60% strain), high sensitivity [gauge factor (GF) of 11.8 at 60% strain and detection limit of 0.1% strain], fast response ability (response/recovery time of 40/84 ms), and exceptional durability for 800 cycles of fatigue test. Besides, the highly flexible polydimethylsiloxane chains, strong intermolecular hydrogen bonding, and dynamic exchange reaction of aromatic disulfides ensure the sensor excellent recovery property of electrical conductivity, and the GF of sensor after self-healed only increases slightly. More importantly, the sensor is successfully applied for detecting a variety of human motions including pulse beats, voice recognitions, various joint movements, and handwriting. The method for preparing room-temperature self-healable strain sensor is facile, scalable, and cost-effective. The finds provide a new perspective on fabricating new-generation high-performance and functional strain sensors for health monitoring, wearable electronics, and intelligent robots.

Spatially, Spectrally Single-Mode and Mechanically Flexible 3D-Printed Terahertz Transmission Waveguides

“…7(c), there is a quasi-linear relationship between the strain of waveguides and tensile force. The strain ε was calculated according to the following formula [54]:…”

Multi‐functional polyurethane composites with self‐healing and shape memory properties enhanced by graphene oxide

“…The XRD image in Figure 1(a) shows the (002) reflection of GO appears at 2θ = 10.68 . 10 As shown in Figure 1(b), the Raman spectrum of GO shows prominent D peak at 1325 cm −1 and G peak at 1575 cm −1 which indicates a typical GO structure. 10 In order to understand the hybrid structure, polyurethane composite was analyzed by FTIR.…”

“…The first kind of healing mechanism is extrinsic self-healing. The healing agent (pre-embedded in the microcapsules 10 or microvascular networks 11 ) is encapsulated into the polyurethane matrix; once the polyurethane matrix is destroyed, the healing agent can be released to the damage zone by capillary forces to heal the cracks. The second kind of healing mechanism is intrinsic self-healing.…”

Recent progress for silver nanowires conducting film for flexible electronics

“…AgNWs could be dispersed in many solvents such as ethanol, isopropanol and water with good solubility, so the AgNW-based conducting films are often manipulated in a solution process [ 137 – 143 ]. The AgNWs solution is transferred to the flexible matrix to fabricate conducting films by techniques such as printing, coating, vacuum filtration, template-assisted assembly and gelation [ 144 – 149 ].…”