Highly Sensitive and Stretchable Strain Sensor Based on a Synergistic Hybrid Conductive Network

Abstract

Highly sensitive and stretchable strain sensors have attracted considerable attention due to their promising applications in human motion detection, soft robot, wearable electronics, etc. However, there is still a trade-off between high sensitivity and high stretchability. Here, we reported a stretchable strain sensor by sandwiching reduced graphene oxide (RGO)-coated polystyrene microspheres (PS@RGO) and silver nanowires (AgNWs) conductive hybrids in an elastic polydimethylsiloxane (PDMS) matrix. Due to the synergistic effect of PS@RGO and AgNWs, the PDMS/PS@RGO/ AgNWs/PDMS sensor exhibits a high initial electrical conductivity of 8791 S m −1 , wide working range of 0−230%, large gauge factor of 11 at 0−60% of strain and 47 at 100%−230% of strain with a high linear coefficient of 0.9594 and 0.9947, respectively, low limit of detection (LOD) of 1% of strain, and excellent long-term stability over 1000 stretching/releasing cycles under 50% strain. Furthermore, the strain sensor has been demonstrated in detecting human body motion and fan rotation with high stretchability and stability, showing potential application in intelligent robot and Internet of things.

Flexible Strain Sensors for Wearable Hand Gesture Recognition: From Devices to Systems

“…A type of effective approach is to use the nanocomposite materials to form the conductive mesh structure to maintain electrical conduction paths in the elastic composite at large strain. [ 15,25,45–59 ] Huang et al used the CNT network as the mesh structure, which bridged dispersed silver nanoparticles (AgNPs) in thermoplastic polyurethane electrospun membrane (TPUEM) ( Figure a). [ 45 ] Compared with the sensor device without CNTs, the stretchability of the sensor was improved to 550%, and a high GF of 7066 at 500% strain was achieved (Figure 3b).…”

“…Similarly, Liu et al reported a stretchable strain sensor by sandwiching reduced graphene oxide (RGO)‐coated polystyrene microspheres (PS@RGO) and silver nanowires (AgNWs) in an elastic polydimethylsiloxane (PDMS) matrix. [ 46 ] High‐aspect‐ratio AgNWs were used to connect the adjacent PS@RGO microspheres to prevent the electrical failure of the sensor at large strain. By adjusting the AgNW concentration, the sensor exhibited capability of measuring a wide range strain up to 230% with a large GF of 11 at 0−60% of strain and 47 at 100−230% of strain.…”

Smart Textile Based on 3D Stretchable Silver Nanowires/MXene Conductive Networks for Personal Healthcare and Thermal Management

“…To solve the above limitations, it is essential to construct novel mechanically stretchable and multifunctional conductive networks on breathable substrates. Although conducting polymers, , metal particles, , and carbon-based materials such as CNTs − and graphene , have been successfully developed in recent years, the serious aggregation of metal particles, the low electrical conductivity and environmental instability of conducting polymers, and the high contact resistance between carbon-based materials lead to performances that are far from what is expected. Furthermore, the assembly of microscopic conductive units such as nanoparticles, nanotubes, and nanosheets into high-performance interconnected macroscopic conductive networks is still challenging due to the weak interfacial contacts between the units, which seriously decrease the stretchability and sensitivity of wearable electronics.…”

Synthesis of a grape-like conductive carbon black/Ag hybrid as the conductive filler for soft silicone rubber

“…Conductive carbon materials and metal llers are oen used together to reinforce the electrical conductivity or mechanical properties of the composites by simple mixing 31,32 or mutual modication. [33][34][35] When this hybrid ller is used to fabricate lled conductive composites, it shows good dispersibility in the matrix.…”