Precisely Patterning Graphene Sheets through a Liquid‐Bridge Induced Strategy

Abstract

is inhomogeneity of gradient polymeric stripes with wide outer stripes and narrow ones near the centre. Another limitation of this method is the orientation of graphene stripes, in which all the graphene assemblies were towards the same direction. Therefore, on-demand positioning of graphene onto desired substrates remains a relatively unexplored subject and a signifi cant scientifi c challenge. Recently, a "liquid bridge induced assembly" strategy has been reported to successfully assemble small molecules, [ 30 ] polymers, [ 31 ] biomarcromolecules, [ 32 ] nanoparticles [ 33 ] and microspheres. [ 34 ] Diverse building blocks insides liquid bridges can be guided to assemble into one dimensional architectures with precisely positioning, allowing a promising avenue for precise graphene patterning.Herein we report precisely positioning graphene patterns by means of liquid-bridge induced process. Regular micropillars play an important role in mediating the alignment of liquid bridges, yielding controlled position/orientation of graphene assemblies. The cooperation between liquid surface energy and the concentration of graphene suspension contributes to the successful/failed patterning. Since this method enables to pattern graphene upon both hard silicon and soft polydimethylsiloxane (PDMS) substrates, a fl exible graphene-assembly-based circuit can be generated. Electrons can stop/pass this bending-sensitive circuit depending on pressing/relaxing the graphene/polymer fi lm. We believe the present approach will advance existing applications of patterning graphene in industry application, bringing a new alternative to some commercially available optoelectronic devices.Ordered one dimensional nanoarchitectures generated by previous "liquid-bridge induced" methods [30][31][32][33][34] are commonly suspended in air and have to be pressed onto fl at wafers for further device application, indicating a complex transfer process and considerable structural damages. Therefore, a sandwich-shaped assembly system has been proposed in this study, shown in Figure 1 . This improved assembly system can directly pattern building blocks upon desired fl at substrates by only one step, allowing a rapid, high-through and low-defect strategy for controlling graphene positioning. Detailedly, commercial graphene sheets with few atomic layers (Supporting Information Figure S1) have been mixed with a certain surfactant (sodium dodecyl benzene sulfonate, SDBS, which can be removed by ethanol washing after assembly) to increase their dispersion in water. Then, 10 μL droplet of this dark suspension was carefully dropped onto Liquid FilmsGraphene has been attracting much attention owing to its fascinating physical properties such as quantum electronic transport, [ 1,2 ] extremely high mobility, [ 3 ] high elasticity [ 4 ] and electromechanical modulation, [ 5,6 ] allowing broad technological implications for areas ranging from fi eld effect transistors, [7][8][9] highly effective sensors, [ 10 ] transparent conductive fi lms [ 11 ] to clean energy...

Line-patterning of polyaniline coated MWCNT on stepped substrates using DC electric field

“…Therefore, numerous efforts from both scientific and industrial communities have been made to achieve high resolution inkjet-printed features by shrinking the nozzle size4 or control of interfacial tension between ink and substrate or nozzle material5. However, the high resolution, less than 1 μm in line width, has not been achieved with conducting ink such as silver, copper, carbon nanotube (CNT), conducting polymers and indium tin oxide (ITO) by the common inkjet printing technique1678 although various materials are patterned one-dimensionally by techniques of several process steps910. Recent advance in inkjet printing techniques such as electrostatic autofocussing11, electrohydrodynamic jet12, electrified liquid jet13, and dielectrophoretic nanoprinting14 allows the fabrication of high resolution line-pattern which is less than 1 μm of line width.…”

Superwettability Strategy: 1D Assembly of Binary Nanoparticles as Gas Sensors

“…It should be noted that the above‐mentioned studies of binary NP assembly have been mainly focused on the terms of 2D/3D scales, whereas their performance in 1D is still an open question. Recently, superwettability mediated 1D assembly strategy provides a feasible yet effective way to divide liquids into ordered stripe domains, allowing strictly linear assembly of diverse single‐component building blocks, including graphene sheets, semiconductor quantum dots, and metallic NPs . To date, little was reported about fabricating ordered 1D assemblies of binary/multi‐NPs by such a superwettability strategy, and their assemblies are clearly of paramount importance for the ability to manipulate and optimize their function through coupling effects.…”

Top‐Pinning Controlled Dewetting for Fabrication of Large‐Scaled Polymer Microwires and Applications in OFETs

“…[ 8 ] However, due to the long chain and high molecular weight characteristics of polymers, [ 2 ] the absence of controlled dewetting in these methods may lead to uncontrolled stacking of the polymer molecular chains which will infl uence the charge transport and harm performances of the devices. [ 2,9 ] Recently, a new strategy was demonstrated effective for assembling nanoparticles, [ 10 ] graphene, [ 11 ] small organic molecules, [ 12 ] and polymers [ 13 ] by employing pillar-structured surfaces and confi ned assembling induced by dewetting of 1D liquid-bridges on wileyonlinelibrary.com the solvent particles evaporate to the air phase gradually. The concentration of the solution layer ascends continuously and at a certain stage, the solution layer breaks into large pieces ( Figure S1, Supporting Information) because of the dewetting and shrinking during solvent evaporation.…”

“…The parameters of the as-prepared polymer arrays can be tailored by changing the width and spacing of the silicon pillar template. [ 10,11,20 ] As can be seen from Figure 6 a, microstripe wileyonlinelibrary.com arrays with width ranging from 2 to 5 µm with 2 µm distance could be generated. These processes provide new thoughts for developing patterned structures in more contact state.…”

“…Recently, a new strategy was demonstrated effective for assembling nanoparticles, graphene, small organic molecules, and polymers by employing pillar‐structured surfaces and confined assembling induced by dewetting of 1D liquid‐bridges on the interface. This technology exhibits great potential in assembling polymer structures for electronic devices because the molecules will be aligned in controlled manner.…”