Scratch tests were done on Si-C-N coatings developed on Si (100) substrates useful for MEMS devices in unconducive environments. The interfacial adhesive strength got manifested in different failure morphologies. The features depicting their chronological failures were analyzed by relating the load-scratch length plots with the scratch track image. The cohesive and adhesive strength were found to be independent to each other with each of them getting manifested in different ways.

Biosensors are an integral part of medical diagnostics. The materials, as well as the structural makeup used in these devices, are being upgraded through various solid-state processes, chemical processes, and micro-machining techniques. The material porous Silicon (PSi) has biosensing capabilities that can cause immobility of the attached biomolecules in its pores. The variation in porosity with current density was presented and related to the different etched stages of the silicon surface. PSi is a novel patterned cantilever MEMS resonator membrane that can be utilized for high-precision biosensing. Finite element modeling shows the strain distribution in the novel design. A theoretical base of the coupled oscillations in the sensors for the difference in dimension separation and absorbance was given.

Scratch tests were done on thermally resistant hard Si-C-N coatings developed on glass substrates using magnetron sputtering. The change in loading rate and coating thickness showed variation in adhesion strength and wear, The Boussinesq, Hans and Blister stress distribution beneath the indenter had on effect of the failure processes. Elastic recovery was prevalent in coatings of higher thickness and higher rate of loading. The increased loading rate although caused early failure but resulted in less wear.

Scratch tests were performed on thermal resistant hard Si-C-N coatings deposited on steel (SS) 304, by RF (Radio frequency) magnetron sputtering. The abrasion and wear properties were studied by analyzing the changing failure complexion inside the scratch showing a mixture of ductile and brittle properties The change in loading rate caused noticeable changes in the failure mode. The plasticity was found to have a peripheral domination initially with increase in load but was replaced by brittle failure on increasing the loading rate. The work of adhesion and wear rate were determined.