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A micro-corrosion sensor technology utilizing PDMS (polydimethylsiloxane) and micro/nano -metal particles, as the
sensing element, was proposed and currently under-development. One of the key challenges encountered is the removal
of the native oxides inherently existing on the metal particles. Numerous techniques were experimented to counter this
problem, with swell-based protocols being identified as the most promising solution. Swelling of the composite
enhances the diffusion of oxide etchants into and etched oxides out of the material matrix. Two different swelling
characterizations, utilizing liquid-based solvents and supercritical CO2 emersions, will be presented here. In terms of
compatibility, common microfabrication solvents were used to evaluate the former, while supercritical CO2 is often used
in the release of stiction sensitive microstructures. Both methods are classified as low temperature techniques (less than
100 degrees Celcius). Commonly, the composite exhibits a swelling ratio of 10-20%, exhibiting more sensitive to the
percentage content of the metal particles albeit well below those reported in literature for pure cross -linked PDMS. The
swelling time-constant is found to be on the order of minutes (CO2) to tens of minutes (liquid solvent) while oxide
removal for cubed coupons with 6.35mm on each side is on the order of hours. Also in both cases, the oxide etching
performance is dependent on the amount of dilation of the material and the mixing compatibility between the swelling
agent and the etchant (such as acetic acid and hexafluoroacetylacetone, respectively for copper oxides). The etch
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