BCMaterials Fortnightly Seminar #97

PAULA GONZÁLEZ

(BCMATERIALS)

Increasing the sensitivity of magnetoelastic sensors by modifying the geometry.

Magnetoelastic resonators are gaining interest for sensors applications, due to be a wireless, cheap and quick method for the detection of low amounts of chemical or biological compounds. In that systems, the sensitivity and the selectivity are two important parameters that define the quality of the sensor. For that reason, many investigations are focus on the increase of that sensitivity, however, most of them are focus on the same thing, increase the sensitivity by reducing the sensor length. In this work, a commercial Fe40Ni38Mo4B18 metallic glass (Metglas 2826MB) have been used to study the effect of the geometry of the sensor and of the percentage of the resonator surface covered on the sensitivity of the sensor. Results shows that, changing the geometry of the resonator without change the length, an increase of more than a 500% on its sensitivity which respect to the traditional rectangular shape could be achieve.

CRISTIAN MENDES

(BCMATERIALS)

Electro-mechanical properties of UV-curable piezoresistive composites for sensor applications.

Piezoresistive polymer-based composites have attracted increasing attention due to the number of polymers and nanofiller materials potential combinations, allowing tailoring material properties for specific applications, ranging from automotive components to medical devices. Among the different nanofillers, carbon nanotubes (CNT) have excellent electrical and mechanical properties, as well as high aspect ratio, being therefore excellent fillers for the development of piezoresistive and/or conductive composites. As for the polymer-based matrix of these composites, UV radiation-curable polymers are getting increasing relevance as they are environmentally-friendlier materials (no solvent emission-evaporation) and require low energy for curing, when compared to other conventional heat curable products. Furthermore, this technique is faster, obtains better patterns and works at room temperature. For all of that, MWCNT/polyurethane acrylate resin (MWCNT/PUA) composites with optimized piezoresistive response by UV-curing process have been developed. The morphological, thermal, mechanical, electrical and electro-mechanical properties of the composites are investigated as a function of multi-walled carbon nanotubes content.