Can charge writing aid nanotechnological manipulation?

Abstract

Significant progress in the examination or manipulation of submicrometre particles and large molecules is likely to be dependent upon a suitable method in locating and orienting them onto working substrates. Ideally this would be a general purpose tool that allowed local programming to attract selectively species of interest. Charge writing onto electrets with a scanning-probe microscope offers one possible method. Here the use of this technique for memory applications (the only significant body of research) is examined in order to judge the feasibility of using it with different operational parameters for 'electrostatic clamping'. Until recently it was not regarded as practicable, but new materials developments, especially oxide-nitride-oxide-silicon electrets, show considerably more promise. A clear answer to our question cannot yet be given, but further investigations are suggested and recommended.

Submicrometer Patterning of Charge in Thin-Film Electrets

“…Because we could pattern charge with current densities Ͻ1 mA/cm 2 -a thermal energy 10 4 smaller than what is needed to melt the PMMA-we conclude that bulk, heat-induced melting and flow are not necessary for patterning, but we cannot preclude surface flow on scales of a few nanometers as a result of current-induced warming and electrostatic pressure. We believe that the ability to generate high-resolution patterns of trapped charge can, in principle, be used (i) for information storage, (ii) for second-harmonic generation of optical waves traveling along a surface (18-21), (iii) to deplete and pattern regions of a two-dimensional electron gas (22, 23) near a semiconductor surface, and (iv) to allow the realization of a charge-based printing technique analogous to xerography of small particles and possibly molecules (24). Figure 5 shows an initial example of charge-based printing of particles.…”

Assembly of Nanoparticles: Towards Multiscale Three-Dimensional Architecturing

“…Localized charge patterns have been widely utilized to make patterns of nanoparticles because, just by exposing the substrate to a suspension of nanoparticles, the particles experience long-range Coulomb interactions and are selectively deposited on the charged area of the substrate [30][31][32] . A stainless-steel needle was used to create lines of negative charges by contact charging on the surface of a oxidized silicon substrate 33) .…”

Gas Phase Nanoparticle Integration

“…The nanomaterial building blocks would not have to be transferred in solution as is currently the case. Solution concepts have their own set of problems -almost all of the reviewed receptor based assembly concepts [1,2,[5][6][7][8][9][10][11][12][13] require surface functionization to prevent agglomeration or to guide the assembly which often interferes with the electronic or optical properties. Direct integration from the gas phase would support the use of well established passivation concepts to create high quality nanomaterial building blocks that maintain the electronic and optoelectronic functionality.…”