Enhanced Electrical Networks of Stretchable Conductors with Small Fraction of Carbon Nanotube/Graphene Hybrid Fillers

Abstract

Carbon nanotubes (CNTs) and graphene are known to be good conductive fillers due to their favorable electrical properties and high aspect ratios and have been investigated for application as stretchable composite conductors. A stretchable conducting nanocomposite should have a small fraction of conductive filler material to maintain stretchability. Here we demonstrate enhanced electrical networks of nanocomposites via the use of a CNT-graphene hybrid system using a small mass fraction of conductive filler. The CNT-graphene hybrid system exhibits synergistic effects that prevent agglomeration of CNTs and graphene restacking and reduce contact resistance by formation of 1D(CNT)-2D(graphene) interconnection. These effects resulted in nanocomposite materials formed of multiwalled carbon nanotubes (MWCNTs), thermally reduced graphene (TRG), and polydimethylsiloxane (PDMS), which had a higher electrical conductivity compared with MWCNT/PDMS or TRG/PDMS nanocomposites until specific fraction that is sufficient to form electrical network among conductive fillers. These nanocomposite materials maintained their electrical conductivity when 60% strained.

From stretchable to reconfigurable inorganic electronics

“…demonstrated that in CNT-Graphene-PDMS hybrid fillers, the synergistic effects in the CNTgraphene mixture prevent agglomeration of CNTs and the restacking of graphene to improve electrical performance while maintaining high stretchability [83] (Figure 3c). …”

“…Schematic displays the interaction between CNTs and graphene. Reprinted with permission from [83] . Reprinted with permission from [97] .…”

Novel porous nanohybrid materials with unexpected mechanical and electrical performance by pyrolysis of carbon nanotube-filled benzoxazine thermosets

“…26 For other comparison, the electrical conductivity of a pellet of CNTs obtained by compression was only of 10 S cm −1 which is close to the reported value of the macroscopic electrical conductivity of MWCNTs. 24 The relatively low conductivity of the pellet of CNTs compared to the conductivity of one single tube may be imparted to a poor contact between each tube. The pyrolysis appears thus to generate a carbonaceous cement binding the CNTs all together, forming a dense network and therefore promoting good electrical contact.…”

“…For instance, a polydimethylsiloxane matrix is found to reach a conductivity of around 10 −1 S cm −1 in the presence of 5 wt% CNTs. 24 Higher electrical conductivity may be obtained by increasing dramatically the CNT content, up to 50 wt%, entering in this case the area of the so-called buckypapers. For example, Chapertegui et al 25,26 were able to prepare a CNT-Benzoxazine buckypaper showing a very interesting electrical conductivity, close to 30 S cm −1 .…”

Facile Fabrication of Stretchable Electrodes by Sedimentation of Ag Nanoparticles in PDMS Matrix

“…Stretchable electrodes are one of the key components of future electronic devices such as flexible and stretchable displays, strain sensors, actuators, nanogenerators, and wearable electronic devices [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Thus, simple and cost-effective processes for the fabrication of stretchable electrodes will be in high demand.…”