Large‐Scale Assembly of Single Nanowires through Capillary‐Assisted Dielectrophoresis

Abstract

An innovative technique is proposed for the precise and scalable placement of 1D nanostructures in an affordable manner. This approach combines the dielectrophoresis phenomenon and capillary assembly to successfully align thousands of single nanowires at specific locations at the wafer. The nanowires are selectively trapped by taking advantage of the material--specific frequence dependence.

Precise Patterning of Organic Single Crystals via Capillary‐Assisted Alternating‐Electric Field

“…Capillary force ( F c ) and alternating‐electric field (AEF) have been reported to be effective for the assembly of postgrowth nanocrystals . Cui et al reported the hierarchical assembly of isotropic and anisotropic colloidal nanostructures over large areas by capillary force.…”

“…For instance, Freer et al adopted F DEP to manipulate and address silicon nanowires in large area . Collet et al combined F DEP and F c to pattern silicon nanowires . Besides the silicon nanowires, recently the electric field was utilized to achieve in situ growth and patterning of organic single crystals on electrode patterns .…”

“…This force can prevail over other forces (e.g., hydrodynamic drag, electrothermal, intraparticle, and surface–particle adhesive forces) to induce the micro/nanocrystals to migrate directionally in the solution and finally localize at specific predefined positions. The F DEP can be given by: where Γ is a constant that depends on the shape and dimension of particle, ε m is the complex dielectric constant of the medium, ▽ E 2 is the gradient of the square modulus of the electric field, K (ω) is a function of the angular frequency of the applied field ω, and R e[ K (ω)] is the real part of Clausius–Mossoti factor, which is frequency‐dependent. R e[ K (ω)] is positive at lower frequencies and becomes negative at higher frequencies.…”

Concept for assembling individual nanostructure-based components into complex devices

“…39 And even more resource efficient parallel and unsupervised assembly processes can be also potentially adopted for this. [26][27][28][29] Hence, the assembly process may be further streamlined substantially lowering the associated costs.…”

“…So far such integration has been demonstrated only for micrometer-scale components, 12,[19][20][21][22][23][24][25] and it has been shown that heterogeneous integration can be done in a very efficient way by parallel and unsupervised self-assembly. [26][27][28][29] Micro-and nanoscale components are typically fabricated on rather thick (down to 25 lm, typically 200-300 lm thick) and large (down to 25 lm, typically 5-15 mm lateral dimensions) dies due to practical limitations regarding die a) Present address: International Iberian Nanotechnology Laboratory, Av.…”