Showing papers by "Vittorio Scardaci published in 2012"

Spray deposition of Silver Nanowire transparent conductive networks

Abstract: We investigate Silver Nanowire (AgNW) networks, deposited by spray coating, on a flexible plastic substrate, for application as transparent electrodes for Indium Tin Oxide (ITO) replacement. We demonstrate that the network performance is controlled by the size distribution of the droplets impinging the substrate. Droplet size distribution can be controlled by tuning the spray pressure. Under the most favorable conditions, we achieve networks with typical transmittance T∼90% and sheet resistance Rs∼50Ω/□, and Rs∼1kΩ/□ at T∼94%.

Carbon Nanotube network based sensors

Abstract: We demonstrate three types of sensors based on spray-deposited Carbon Nanotube (CNT) networks on flexible substrates: humidity sensors, dew-point sensors and time-temperature indicators. The presence of Sodium Dodecylsulphate (SDS) significantly increases the sensitivity of the film resistance of CNT networks to changes of relative humidity. We observe up to a 3% change in film resistance in the 30–75% range of relative humidity, with a non-linear relationship. When these SDS-impregnated CNT films are cooled to the dew-point of air, with the temperature of the film monitored, the associated increase in sheet resistance can be used to establish the dew-point temperature. We use acid-doped CNT networks as time-temperature indicators, exploiting the de-doping of the CNT networks at higher temperature. We observe an increase in film resistance of such networks at temperatures higher than 50 °C. The rate of the resistance increase follows the Arrhenius law. The extent of the resistance increase ranges from ∼30%at 50 °C to >300% at 100 °C.