*********************************
There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
*********************************
Atlanta, GA | Posted: January 8, 2015
Summary Sentence:
A team from Georgia Tech have measured the mechanical properties of soft contact lenses under practical conditions using an atomic force microscope (AFM).
Full Summary:
No summary paragraph submitted.
Tsukruk in LabContact lenses have to fulfil a number of contradictory functions while remaining optically clear – they need to be flexible enough to make them comfortable, but must also maintain their shape in saline conditions. Current mechanical characterisation of lens materials is based solely on tensile tests, which measure only the averaged elastic modulus of the entire lens. With coatings and wetting agents widely used in the latest multiphase lenses, it is becoming increasingly important to measure the local mechanical properties of these materials.
Led by Vladimir V. Tsukruk, Georgia Tech engineers turned to AFM-based surface force spectroscopy (SFS) to characterise the micromechanical properties of commercial contact lenses at the nanoscale. This technique has been used to study surface topography, friction, and protein absorption in contact lens materials and in eye tissue, but the paper from Tsukruk (Polymer 55 (2014) 6091–6101 [DOI: 10.1016/j.polymer.2014.09.053]) is the first to probe the surface mechanical properties in wet conditions. The team’s technique combined two AFM modes - high frequency (tapping mode) measurements, which provide high resolution maps of topography and mechanical properties, and static (force volume) nanoindentation, which utilises tip sample interactions to accurately calculate mechanical properties.
Read more about the research here.
