Biomedical subjects

Brian Y Chow

Publications and source records attributed to Brian Y Chow.

3 recordsLinked to original sources

PubMed2006

Solid-state bonding technique for template-stripped ultraflat gold substrates.

A simple procedure using gold diffusion bonding for the preparation of template-stripped gold (TSG) surfaces is described. TSG surfaces are useful for surface studies because a very consistent flat gold surface with few defects can be easily prepared. We have developed a method of producing TSG surfaces that relies only on gold diffusion bonding rather than epoxies. The resulting substrates are free from concerns of solvent compatibility, heat stability, and impurities. Bonding of centimeter-sized substrates is performed at 300 degrees C for 2 h using a vise and aluminum foil.

Journal Article↗

PubMed2006

Nanoscale patterning on insulating substrates by critical energy electron beam lithography.

This Letter describes a method to generate nanometer scale patterns on insulating substrates and wide band gap materials using critical energy electron beam lithography. By operating at the critical energy (E2) where a charge balance between incoming and outgoing electrons leaves the surface neutral, charge-induced pattern distortions typically seen in e-beam lithography on insulators were practically eliminated. This removes the need for conductive dissipation layers or differentially pumped e-beam columns with sophisticated gas delivery systems to control charging effects. Using a "scan square" method to find the critical energy, sub-100 nm features in 65 nm thick poly(methyl methacrylate) on glass were achieved at area doses as low as 10 microC/cm2 at E2 = 1.3 keV. This method has potential applications in high-density biochips, flexible electronics, and optoelectronics and may improve the fidelity of low voltage e-beam lithography for parallel microcolumn arrays.

Electric Conductivity↗

PubMed2005

Perfecting imperfect "monolayers": removal of siloxane multilayers by CO2 snow treatment.

Self-assembled monolayers (SAMs) of N-(3-triethoxysilylpropyl)-4-hydroxybutyramide were prepared on silicon oxide on silicon (Si/SiO(2)). Initial silane adsorption and high-temperature annealing led to a stable base monolayer with many large over-lying islands of disordered multilayers as a result of the non-self-limited growth process. The disordered multilayers were hydrolyzed and subsequently removed by CO(2) snow treatment. The resulting films were one monolayer thick as measured by ellipsometry. Atomic force microscopy, attenuated total reflection Fourier transform infrared spectroscopy, and contact angle analysis showed that the films were composed of monolayers with full and uniform surface coverage rather than nonuniform coverage by islands or patches of multilayers. Monolayers of octadecyltrichlorosilane were also prepared by multilayer removal via CO(2) treatment, showing the general applicability of the technique toward siloxane SAMs. We believe that CO(2) is an excellent solvent for weakly bound and hydrolyzed molecules that compose multilayers, and this ability to prepare near-perfect monolayer films from imperfect ones allows for less stringent formation conditions.

Journal Article↗