Open Access. Powered by Scholars. Published by Universities.®

Nanoscience and Nanotechnology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Nanoscience and Nanotechnology

Metal-Assisted Etching Of Silicon Molds For Electroforming, Ralu Divan, Dan Rosenthal '14, Karim Ogando, Leonidas E. Ocola, Daniel Rosenmann, Nicolaie Moldovan Sep 2013

Metal-Assisted Etching Of Silicon Molds For Electroforming, Ralu Divan, Dan Rosenthal '14, Karim Ogando, Leonidas E. Ocola, Daniel Rosenmann, Nicolaie Moldovan

Student Publications & Research

Ordered arrays of high-aspect-ratio micro/nanostructures in semiconductors stirred a huge scientific interest due to their unique one-dimensional physical morphology and the associated electrical, mechanical, chemical, optoelectronic, and thermal properties. Metal-assisted chemical etching enables fabrication of such high aspect ratio Si nanostructures with controlled diameter, shape, length, and packing density, but suffers from structure deformation and shape inconsistency due to uncontrolled migration of noble metal structures during etching. Hereby the authors prove that a Ti adhesion layer helps in stabilizing gold structures, preventing their migration on the wafer surface while not impeding the etching. Based on this finding, the authors ...


Nanoscale Surface Roughness Affects Low Reynolds Number Flow: Experiments And Modeling, Robert Jaeger, Jing Ren, Yu Xie, Sriram Sundararajan, Michael G. Olsen, Baskar Ganapathysubramanian Jan 2012

Nanoscale Surface Roughness Affects Low Reynolds Number Flow: Experiments And Modeling, Robert Jaeger, Jing Ren, Yu Xie, Sriram Sundararajan, Michael G. Olsen, Baskar Ganapathysubramanian

Mechanical Engineering Publications

Most micro-channel fabrication strategies generate nano-to-micro-scale, stochastic surface roughness. This inherent stochasticity can potentially be harnessed to direct microfluidic operations such as self-cleaning behavior and localized mixing. This work investigates the effect of stochastic nanoscale roughness on low to moderate Reynolds number Newtonian flow using concurrent modeling and experiments. We fabricate a microscopic channel with tailored hydrofluoric-acid-etched rough surfaces. Optical profilometry and micro-particle-image-velocimetry (micro-PIV) are used to characterize the surface roughness and flow field and is integrated with direct numerical simulation that resolves effects of nanoscale roughness. Results indicate that nanoscale roughness causes flow perturbations that extend up to the ...


Generating Random Surfaces With Desired Autocorrelation Length, Yilei Zhang, Sriram Sundararajan Jan 2006

Generating Random Surfaces With Desired Autocorrelation Length, Yilei Zhang, Sriram Sundararajan

Mechanical Engineering Publications

A versatile surface processing method based on electrostatic deposition of particles and subsequent dry etching is shown to be able to tailor the autocorrelation length of a random surface by varying particle size and coverage. An explicit relation between final autocorrelation length, surface coverage of the particles, particle size, and etch depth is built. The autocorrelation length of the final surface closely follows a power law decay with particle coverage, the most significant processing parameter. Experimental results on silicon substrates agree reasonably well with model predictions.


The Effect Of Autocorrelation Length On The Real Area Of Contact And Friction Behavior Of Rough Surfaces, Yilei Zhang, Sriram Sundararajan Jan 2005

The Effect Of Autocorrelation Length On The Real Area Of Contact And Friction Behavior Of Rough Surfaces, Yilei Zhang, Sriram Sundararajan

Mechanical Engineering Publications

Autocorrelation length (ACL) is a surface roughness parameter that provides spatial information of surfacetopography that is not included in amplitude parameters such as root-mean-square roughness. This paper presents a relationship between ACL and the friction behavior of a rough surface. The influence of ACL on the peak distribution of a profile is studied based on Whitehouse and Archard’s classical analysis [Whitehouse and ArchardProc. R. Soc. London, Ser. A316, 97 (1970)] and their results are extended to compare profiles from different surfaces. The probability density function of peaks and the mean peak height of a profile are given as functions ...