Mesoporous MOS devices: a platform for nanofluidic studies

GIMENEZ, ROCÍO; DELGADO, DIANA C.; D. CORSO; PALUMBO, FÉLIX; S. LIBERTINO; BERLI, CLAUDIO L. A.; BELLINO, M.G.

Workshop; 1st Argentine-German Workshop on Nanotechnology and Nanobiosensors; 2017

Mesoporous films present an important and challenging interestfor their use as matrices for the transport of fluids. Its potentialapplications range from its use in fuel cells to biomedicine.Finding variants for the detection and monitoring of fluids withinsystems is a topic of real interest, both from the basic point ofview for characterization of nanosystems and for its transcendentapplications.Our research aims at the use of electrical capacitancemeasurements to observe fluids dynamics within mesoporousfilms. To this end, MOS (Metal Oxide Semiconductor) systemswere fabricated by placing a mesoporous silicon oxide filmbetween a copper or gold metal contact and a siliconsemiconductor substrate. The presence of different fluids withinthe porous system was observed through capacitance measurements. The capacitance of the system increasedprogressively and significantly during the capillary imbibition ofthe nanoporous matrix, and then decreased during the process ofevaporation of the liquid. The curves obtained show the differentcharacteristics of the fluids used.For the description and theoretical interpretation of the results weused a model based on the progressive change of the electricalpermeability of the pores by their individual filling and theinfluence within the oxide considered as an effective medium.These preliminary results open a promising field for a noveltechnique for the characterization of nanosystems analyzingfluids dynamics in nanoporous networks, as well as thefabrication of nanofluidic devices for various applicationsincluding advanced sensors.