Spray-Processed Composites with High Conductivity and Elasticity

Abstract

Highly conductive elastic composites were constructed using multistep solution-based fabrication methods that included the deposition of a nonwoven polymer fiber mat through solution blow spinning and nanoparticle nucleation. High nanoparticle loading was achieved by introducing silver nanoparticles into the fiber spinning solution. The presence of the silver nanoparticles facilitates improved uptake of silver nanoparticle precursor in subsequent processing steps. The precursor is used to generate a second nanoparticle population, leading to high loading and conductivity. Establishing high nanoparticle loading in a microfibrous block copolymer network generated deformable composites that can sustain electrical conductivities reaching 9000 S/cm under 100% tensile strain. These conductive elastic fabrics can retain at least 70% of their initial electrical conductivity after being stretched to 100% strain and released for 500 cycles. This composite material system has the potential to be implemented in wearable electronics and robotic systems.

Mechanoresponsive Polymerized Liquid Metal Networks

“…Many design strategies for stretchable electronic materials pair conductive micro-structures, such as metal foils, [9,10] networks of metal/carbon filler, [11][12][13][14][15][16] or fiber meshes, [17][18][19] with elastomeric matrices or substrates. To navigate inherent trade-offs between high initial conductivity and consistency over strain, these materials often utilize geometric patterning, [9,10] wrinkled texturing, [13,20] or strain-alignment effects.…”

“…To navigate inherent trade-offs between high initial conductivity and consistency over strain, these materials often utilize geometric patterning, [9,10] wrinkled texturing, [13,20] or strain-alignment effects. [11,18] While good electrical performance (5,000-10,000 S*cm -1 ) has been reliably maintained over short-medium strains (<300%), these methods struggle to achieve high elongation and cyclic stability. [11,[17][18][19] To overcome these limitations, some strategies to fabricate stretchable conductors have turned to intrinsically stretchable materials such as conductive polymers, [21,22] ionic liquids, [23,24] and liquid metals.…”

“…[11,18] While good electrical performance (5,000-10,000 S*cm -1 ) has been reliably maintained over short-medium strains (<300%), these methods struggle to achieve high elongation and cyclic stability. [11,[17][18][19] To overcome these limitations, some strategies to fabricate stretchable conductors have turned to intrinsically stretchable materials such as conductive polymers, [21,22] ionic liquids, [23,24] and liquid metals. [25,26] While the carrier mobility of conjugated polymers and ionic fluids are low, liquid metals, such as non-toxic gallium alloys, possess higher conductivities needed for applications such as power transfer and RF operation.…”

“…These self-assembled kirigami-like structures artificially increased the path length of the conductor and shielded the system from strain, similar to previously reported kirigami-slit composites, serpentine patterns, and fiber networks. [9,10,[17][18][19][45][46][47][48] Prior systems have demonstrated how in isolation such features are able to mitigate increases in resistance with strain, [13,22,23,49] however, the strength of Poly-LMNs comes from combining an intrinsically stretchable material with sets of self-organizing micro/nanoscale structures that simultaneously increase the productive cross-sectional area in the network with strain while mitigating geometric lengthening effects.…”

Improving the adhesion, flexibility, and hemostatic efficacy of a sprayable polymer blend surgical sealant by incorporating silica particles

“…3A-B. Using silica produces composite fibers with much higher loading of particles compared to previous research on blow spun composites [45]. Such surface nanoarchitectures have been discovered to contribute significantly to the adhesive footpads of small animals, such as the gecko [46].…”