Rough Surface Modeling of PDMS Polymer through Fractal Dimensions

D. Altuve [1], G. Fernandez [1], L. Paredes [2],
[1] Circuits and Electronics Department, Universidad Simón Bolívar, Caracas, Miranda, Venezuela
[2] Faculty of Electronic and Biomedical Engineering, Universidad Antonio Nariño, Tunja, Colombia
Published in 2018

A good approximation of rough surfaces and their random behaviour is very important in some engineering problems. Fractal modelling provide an alternative to generate rough surfaces based in statistically self-similar non-Euclidean geometries, as seen in [Fig. 1]. Through a frequency domain analysis, it's possible to measure the Hurst exponent of a statistically self-similar geometry with an associated spectral power density, and extract the fractal exponent, it may represent a structure as an assemble of unitary self-contained cells. Fractal analysis mixed with Comsol Multiphysics, will be applied in modelling rough surfaces of PDMS polymer of force sensing resistors, based in AC/DC, solid mechanics and MEMS modules. As a result, the fractal model can generate rough surfaces in different coordinate systems, this is an important feature for the study of conductive paths in thin insulating film sensors.