Effect of Ink Molecular Weights and Annealing Conditions on Molecular Transfer Printing

The molecular transfer printing（MTP） technique has been invented to fabricate chemical patterns with high fidelity using homopolymer inks. In this work, we systematically studied the effects of the molecular weights of homopolymer inks and transfer conditions on the MTP process. We explored a large range of molecular weights（~3.5-56 kg·mol^（-1）） of hydroxyl-terminated polystyrene（PS-OH） and hydroxyl-terminated poly（methyl methacrylate）（PMMA-OH） in the MTP process, and found that the resulting chemical patterns on replicas from all five blends were functional and able to direct the assembly of films of the same blends. The transfer temperature and the film annealing sequences had an impact on the MTP process. MTP was sensitive to the transfer temperature and could only be performed within a certain temperature range, i.e. higher than the glass transition temperature（T_g） of copolymers and lower than the rearrangement temperature of the assembled domains. Pre-organization of the blend films was also necessary for MTP since the preferential wetting of PMMA domains at the replica surface might result in the formation of a PMMA wetting layer to prevent the presentation of underlying chemical patterns to the replica surface.

The essential aspect and regular pattern of ion transfer across the liquid-liquid interface

Three empirical rules of interfacial potential and Gibb's energy with the radius,charge number of transfer ions and dielectric constant of organic phase are obtained for the ion transfer across the liquid-liquid interface,which are verified by the transfer of simple anions,dye ions and metal ions facilitated by neutral ionophores across the interface between water and some organic solvents, and deduced theoretically based on the electrostatic interaction of ion and high-permittivity solvent. The rules are proved to be effective of choosing supporting electrolytes and searching for new transfer system which follows the rule that r/n of transfer ion should be larger than that of electrolytes ion in water phase and less than that in organic phase.A rule for judgement of the charge sign of transfer ion is suggested firstly based on the relationship between interfacial half-wave potential and dielectric constant of organic phase.

Development of Ultra-High Density Silicon Nanowire Arrays for Electronics Applications

This article reviews our recent progress on ultra-high density nanowires(NWs)array-based electronics.The superlattice nanowire pattern transfer(SNAP)method is utilized to produce aligned,ultra-high density Si NW arrays.We fi rst cover processing and materials issues related to achieving bulk-like conductivity characteristics from 1020 nm wide Si NWs.We then discuss Si NW-based fi eld-effect transistors(FETs).These NWs&NW FETs provide terrifi c building blocks for various electronic circuits with applications to memory,energy conversion,fundamental physics,logic,and others.We focus our discussion on complementary symmetry NW logic circuitry,since that provides the most demanding metrics for guiding nanofabrication.Issues such as controlling the density and spatial distribution of both p-and n-type dopants within NW arrays are discussed,as are general methods for achieving Ohmic contacts to both p-and n-type NWs.These various materials and nanofabrication advances are brought together to demonstrate energy effi cient,complementary symmetry NW logic circuits.

Electrical properties of sub-100nm SiGe nanowires

In this study, the electrical properties of Si Ge nanowires in terms of process and fabrication integrity,measurement reliability, width scaling, and doping levels were investigated. Nanowires were fabricated on Si Geon oxide（SGOI） wafers with thickness of 52 nm and Ge content of 47%. The first group of Si Ge wires was initially formed by using conventional I-line lithography and then their size was longitudinally reduced by cutting with a focused ion beam（FIB） to any desired nanometer range down to 60 nm. The other nanowire group was manufactured directly to a chosen nanometer level by using sidewall transfer lithography（STL）. It has been shown that the FIB fabrication process allows manipulation of the line width and doping level of nanowires using Ga atoms.The resistance of wires thinned by FIB was 10 times lower than STL wires which shows the possible dependency of electrical behavior on fabrication method.

ENERGY AND MASS TRANSPORT PROCESSES IN THE GRANULAR BED OF AN INDIRECTLY HEATED ROTARY KILN

The transport mechanisms of momentum, mass, species, and energy are investigated in detail for the ro-tary kiln process. The residence time prediction of the granular bed is well improved by considering different flow patterns in the drum. Introducing a mixed flow pattern of the basic slipping and slumping behaviour has the most important effect on the improvement of the residence time prediction. The granular bed is assumed to behave as a Bingham fluid in the active layer of the bed. The transport mechanisms of momentum, species, and energy are modelled on the basis of this assumption and using the kinetic gas theory. Additionally, a mathematical transformation is presented to save computa-tional time. The model results of the temperature field are in very good agreement with experimental data.