An aqueous sensor network is described consisting of an array of sensor nodes that can be randomly distributed throughout a lake or drinking water reservoir. The data of an individual node is transmitted to the host node via acoustic waves using intermediate nodes as relays. Each node of the sensor network is a data router, and contains sensors capable of measuring environmental parameters of interest. Depending upon the required application, each sensor node can be equipped with different types of physical, biological or chemical sensors, allowing long-term, wide area, in situ multi-parameter monitoring. In this work the aqueous sensor network is described, with application to pH measurement using magnetoelastic sensors. Beyond ensuring drinking water safety, possible applications for the aqueous sensor network include advanced industrial process control, monitoring of aquatic biological communities, and monitoring of waste-stream effluents.
A wireless sensor network is presented for in-situ monitoring of atmospheric hydrogen concentration. The hydrogen sensor network consists of multiple sensor nodes, equipped with titania nanotube hydrogen sensors, distributed throughout the area of interest; each node is both sensor, and data-relay station that enables extended wide area monitoring without a consequent increase of node power and thus node size. The hydrogen sensor is fabricated from a sheet of highly ordered titania nanotubes, made by anodization of a titanium thick film, to which platinum electrodes are connected. The electrical resistance of the hydrogen sensor varies from 245 Ω at 500 ppm hydrogen, to 10.23 kΩ at 0 ppm hydrogen (pure nitrogen environment). The measured resistance is converted to voltage, 0.049 V at 500 ppm to 2.046 V at 0 ppm, by interface circuitry. The microcontroller of the sensor node digitizes the voltage and transmits the digital information, using intermediate nodes as relays, to a host node that downloads measurement data to a computer for display.
70This paper describes the design and operation of the sensor network, the titania nanotube hydrogen sensors with an apparent low level resolution of approximately 0.05 ppm, and their integration in one widely useful device.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.