Biomedical subjects

B L Weeks

Publications and source records attributed to B L Weeks.

3 recordsLinked to original sources

PubMed2002

Effect of dissolution kinetics on feature size in dip-pen nanolithography.

We have investigated the effects of humidity, tip speed, and dwell time on feature size during dip pen nanolithography. Our results indicate a transition between two distinct deposition regimes occurs at a dwell time independent of humidity. While feature size increases with humidity, the relative increase is independent of dwell time. The results are described by a model that accounts for detachment and reattachment at the tip. The model suggests that, at short dwell times (high speed), the most important parameter controlling the feature size is the activation energy for thiol detachment.

Journal Article↗

PubMed2001

Coated silica tips for use in high-pressure, high-temperature, scanning tunneling microscopy.

A novel application of coated silica tips for use in high-pressure, high-temperature, scanning tunneling microscopy is introduced. Thermal drift is reduced in the Z-direction due to the low thermal expansion of silica. Virtually, any conducting material that can be evaporated or sputtered can be used as a tip material. Experimental results are shown for tips sputter coated with platinum, along with images obtained.

Journal Article↗

PubMedDate not supplied

A microcantilever-based pathogen detector.

The ability to detect small amounts of materials, especially bacterial organisms, is important for medical diagnostics and national security issues. Engineered micromechanical systems provide one approach for constructing multifunctional, highly sensitive, real-time, immunospecific biological detectors. We present qualitative detection of specific Salmonella enterica strains using a functionalized silicon nitride microcantilever. Detection is achieved due to a change in the surface stress on the cantilever surface in situ upon binding of a small number of bacteria. Scanning electron micrographs indicate that less than 25 adsorbed bacteria are required for detection.

Antibodies, Bacterial↗