Flexible Hybrid Electronics Nanofiber Electrodes with Excellent Stretchability and Highly Stable Electrical Conductivity for Smart Clothing

Abstract

In this paper, a side-by-side, dual-nozzle electrospinning process was used to prepare a flexible hybrid electronics (FHE) material with excellent stretchable properties. A highly stable electrical conductivity was also imparted to the resulting membrane electrodes using silver nanoparticles (AgNPs) and carbon-based nanomaterials of different structures. The AgNP/carbon-based nanomaterials were coated onto bicomponent polymer nanofibers (composed of polyurethane (PU) and polyvinylidene difluoride (PVDF)) on the nanofiber membrane. The FHE nanofiber electrodes were finally integrated into clothing designed to accurately measure human body sensing signals (e.g., electrocardiography (ECG) and electromyography (EMG) signals). To effectively increase the high electrical conductivity, a polymer-type dispersant (polyisobutylene-b-poly­(oxyethylene)-b-polyisobutylene, a triblock copolymer) was used to effectively and stably disperse AgNPs with different particle sizes and carbon-based nanomaterials with different geometric dimensions (e.g., zero-dimensional carbon black, one-dimensional carbon nanotubes, and two-dimensional graphene) through non-covalent adsorption. Moreover, the bicomponent PVDF–PU nanofibers were immersed in a mixed dispersant of AgNPs and carbon-based nanomaterials at low concentrations, and thermal post-treatment was conducted to improve the electrical conductivity. The AgNP/graphene oxide (GO) nanofiber electrode exhibited a continuous phase with a stable material microstructure after 5000 repetitions of 50% tension–tension fatigue testing. The waveform pattern obtained from the proposed AgNP/GO nanofiber electrode was compared with those of traditional ECG and EMG electrodes. The nanofiber web electrode treated with organic/inorganic mixed dispersants and verified via tests of its electrical and fatigue properties was found to be suitable for long-term ECG and EMG monitoring, and it has excellent potential in wearable smart sensors.

Au Nanorods on Carbon-Based Nanomaterials as Nanohybrid Substrates for High-Efficiency Dynamic Surface-Enhanced Raman Scattering

“…The diameter of CNTs ranges from a few nanometers to tens of nanometers, with a length of approximately 1 μm. CNTs have excellent electrical conductivity, chemical stability, mechanical strength, and thermal conductivity properties. − Although the density of CNTs is only one-sixth that of steel, their strength is hundreds of times that of steel. Graphene is a two-dimensional single-layer honeycomb lattice-like material composed of closely arranged carbon atoms .…”

Hybrid Fiber Materials according to the Manufacturing Technology Methods and IOT Materials: A Systematic Review

“…The waveform patterns obtained from the proposed AgNP/GO nanofiber electrodes were compared with conventional ECG and EMG electrodes. Nanofiber web electrodes treated with organic/inorganic mixed dispersants and verified through electrical and fatigue characteristics tests are suitable for long-term ECG and EMG monitoring and have excellent potential in wearable smart sensors [ 62 ].…”

Recent Progress of the Preparation and Application of Electrospun Porous Nanofibers

“…Additionally, by adjusting post-treatment operations, different types of nanofibers, such as carbon nanofibers, metal oxide nanofibers, or composite nanofibers [ 22 , 23 ], can be produced (for instance, by heating nanofibers in different atmospheres). Electrospun nanofibers with various structures can be obtained using different spinning processes and by adjusting spinning parameters appropriately [ 24 , 25 , 26 ], such as porous fibers [ 27 , 28 ], hollow structures [ 29 , 30 ], hollow porous structures [ 31 , 32 ], core–shell fibers [ 33 , 34 , 35 , 36 ], Janus fibers [ 37 , 38 ], beaded fibers [ 39 , 40 ], and side-by-side structures [ 41 , 42 ].…”