25 research outputs found
Building a context rich interface to low level sensor data
Sensor networks play an important role in our modern information society. These networks are used for a variety of activities in different domains, including traffic monitoring, environmental analysis, transport and personal health. In general, systems generate data in their own format with little or no associated semantics. As a result, data must be managed individually and significant human effort is required to analyze data and develop ad-hoc applications for different end-user requirements. The research presented here proposes a holistic and comprehensive approach to significantly reduce the human effort in analyzing networks of sensors. The goal is to facilitate any form of sensor network, enabling users to combine related semantics with sensor data, and facilitate the end-user transformation of data necessary to provide more complex query expressions, and thus meet the analytical requirements
AerosolāJetāPrinted DonorāBlocking Layer for Organic Photodiodes
Organic photodiodes (OPDs) are optical sensors combining high performance, lightweight mechanical flexibility, and processability from solution. Their fabrication by industrial printing techniques opens a wide range of innovative applications for emerging fields in sensing and the Internet of Things. They typically consist of printed multilayers with functionalities to absorb light, to extract charges, or to reduce detection noise. However, the printing of such device architecture poses a challenge as the deposition of a material can lead to disruption of film morphology or intermixing of materials if its solvent interacts with the previously deposited layer. This work proposes a process to print multilayers from the same solvent system utilizing the aerosol-jet technique. By fine adjustment of the aerosol properties through the tube temperature (TTube), the drying time of poly(3-hexylthiophene-2,5-diyl) (P3HT) printed layers is significantly reduced. This allows its deposition onto a P3HT-based bulk-heterojunction (BHJ) without negatively affecting its performance. The additional printed P3HT layer, spatially extends the donor region of the BHJ, providing ideal hole extraction and simultaneous noise reduction by the blocking of injected electrons. This donor blocking layer (DBL) yields a noise reduction of two orders of magnitude in OPDs operated under ā2 V reverse bias
The Development of a Sub-Surface Monitoring System for Organic Contamination in Soils and Groundwater
A major problem when dealing with environmental contamination is the early detection and subsequent surveillance of the contamination. This paper describes the potential of sub-surface sensor technology for the early detection of organic contaminants in contaminated soils, sediments, and landfill sites. Rugged, low-power hydrocarbon sensors have been developed, along with a data-logging system, for the early detection of phase hydrocarbons in soil. Through laboratory-based evaluation, the ability of this system to monitor organic contamination in water-based systems is being evaluated. When used in conjunction with specific immunoassays, this can provide a sensitive and low-cost solution for long-term monitoring and analysis, applicable to a wide range of field applications