G. Burrasca

Wireless Sensor Networks for Distributed Chemical Sensing: Addressing Power Consumption Limits With On-Board Intelligence

Chemicals detection and quantification is extremely important for ensuring safety and security in multiple application domains like smart environments, building automation, etc. Characteristics of chemical signal propagation make single point of measure approach mostly inefficient. Distributed chemical sensing with wireless platforms may be the key for reconstructing chemical images of sensed environment but its development is currently hampered by technological limits on solid-state sensors power management. We present the implementation of power saving sensor censoring strategies on a novel wireless electronic nose platform specifically designed for cooperative chemical sensing and based on TinyOS. An on-board sensor fusion component complements its software architecture with the capability of locally estimate air quality and chemicals concentrations. Each node is hence capable to decide the informative content of sampled data extending the operative lifespan of the entire network. Actual power savings are modeled and estimated with a measurement approach in experimental scenarios.

TinyNose: Developing a wireless e-nose platform for distributed air quality monitoring applications

In this work we present the development and proof of concept testing of a protoype wireless e-nose (w-nose) architecture capable of mesh shaped networking. The proposed w-nose is based on a TelosB by Crossbow Inc. and custom, power aware, TinyOS based components for data gathering and local processing. Sensor nodes are equipped with a small array of nonconductive polymer/CB based chemiresistors operating at room temperature for VOCs indoor monitoring. A properly developed conditioning stage board connects the sensor array to the microcontroller ADC. A single w-nose has been tested in a controlled test chamber for terpenes discrimination, while networked motes operation have been demonstrated in ad-hoc small testing facilities for acetic acid spill detection.

ENABLING DISTRIBUTED VOC SENSING APPLICATIONS: TOWARD TINYNOSE, A POLYMERIC WIRELESS E-NOSE

In this work, we present the development of a novel wireless e-nose platform designed for indoor distributed VOC detection and quantification. The proposed w-nose, called TinyNose, rely on a small polymeric sensor array that is connected to a commercial wireless mote by means of custom developed electronics. A custom developed software architecture allow for signal acquisition, processing and transmission to a data sink where data are stored and/or presented to the remote user. In this work a preliminary assessment of TinyNose capabilities to operate in open air configuration is conducted by using different source of indoor VOC pollution to be detected and classified by the developed architecture.

Effect of the Layer Geometry on Ink-Jet Sensor Device Perfomances

In this work, we report on ink-jet manufactured chemical sensors based on polymer carbon black composites. In particular, in order to study the correlation between ink-jet pattern geometry and device response sensors characterized by sensing layers consisting of polystyrene/carbon black composites lines of various shape and surfaces were fabricated. The morphology of films, the electrical characteristics and time stability of sensors were investigated.

Intelligent Wireless E-Nose for Power Savvy Distributed Chemical Sensing

In this work, we present the preliminary results for a wireless electronic nose platform embedding local sensor fusion component for the analysis of gas mixture in the framework of indoor pollution monitoring. This approach allow for significant reduction of power consumption by exploiting sensor censorship algorithms i.e. avoiding the transmission of uninformative contents to data sink. At the same time local situation assessment capabilities will allow the mote to perform adaptive, local reaction strategies e.g. duty cycle modifications, actuation etc. Performance are encouraging both on discrimination and estimation problem, we believe that a significant performance enhancement can be obtained by using a tapped delay neural network architecture.

INK‐JET PRINTING OF PF6 FOR OLED APPLICATIONS

In the last years there has been much interest in applying ink‐jet printing (IJP) technology to the deposition of several materials for organic electronics applications, including metals, polymers and nanoparticles dispersions on flexible substrates. The aim of this work is to study the effect of ink‐jet deposition of polymer films in the manufacturing of OLED devices comparing their performances to standard technologies. The ink‐jet printed polymer is introduced in an hybrid structure in which other layers are deposited by vacuum thermal evaporation. The electrical and optical properties of the obtained devices are investigated.OLEDs with the same structure were fabricated by spin‐coating a polymer film by the same solution used as ink. Results have been compared to the above ones to determine how the deposition method affects the device optoelectronic properties.

Towards an All Polymeric Electronic Nose: Device Fabrication and Characterization, Electronic Control, Data Analysis

In this work, a wireless electronic nose prototype, called TinyNose, hosting an array of four different polymeric-composite sensors developed at ENEA, is presented. Sensors are fabricated using a carbon black conducting phase dispersed in different polymeric matrices. The prototype has shown interesting results for VOC compounds detection and discrimination purposes during a measurement campaign.