The μ-TA (Scanning Thermal Mcroscopy) - a tool for quantitative surface analysis and surface treatment

Abstract

ABSTRACTThe analytical technique micro-thermal analysis (μ-TA) will be introduced and evaluated. It combines the visualisation power of atomic force microscopy (AFM) and it's ability to image topography, phase shifts, friction, stiffness, and adhesion with the characterisation capabilities of thermal analysis (thermal conductivity, micro-differential thermal analysis and micro-thermo mechanical analysis) resulting in a characterisation of surfaces with respect to their thermal and thermo-mechanical properties. The scanning mode may be used for the inspection of surfaces with respect to their thermal properties using a scanner with an active thermal sensor (heater, height and thermal sensor) as probe (tip), simultaneously acquiring topography, thermal conductivity and thermal diffusivity images. A second mode gives the option to perform a ocal thermo-mechanical analysis of discrete areas of a few square microns (L-TMA and L-CA), and detects at the same time during heating in contact mode changes of the sensor position and the heat flow to the sample in a very short time. Any thermodynamic phase transition, connected with a change in mechanical properties (softening, expansion, melting) and thermal properties (heat of fusion, change of heat capacity) will thus be detected by both methods. Applications for the analysis of especialy soft materials are presented and critically discussed. Moreover, the use of the instrument for controlled surface treatment is demonstrated resulting in the creation of super smooth polymeric surfaces. Furthermore, attempts to determine thermal conductivity's on surfaces on a quantitative matter wil be presented and discussed.