Richard B. Brown - Research
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Integrated Liquid Chemical Sensors for Measuring Pollutants in Precipitation
Graduate Student Researcher: Steven M. Martin
Additional Faculty: Gerald J. Keeler (AOSS)

 On left: Conceptual drawing of thin-film sensor employing anodic stripping voltammetry for detection of heavy metals. On right: Block diagram of the integrated instrumentation for driving the reduction/oxidation reactions and recording the results.

The goal of this research is to develop a microsystem capable of remote, real-time analysis of rainwater. Low-power, low-voltage, integrated instrumentation is being used to detect the picoampere currents produced by the sensors without introducing large amounts of noise.  This integrated functionality also allows for sensors to be made physically smaller and to reduce the number of sites used for a single recording.  Consequently, arrays of single-use devices can be fabricated that allow for many different analyses from a single chip.  Introduction of other types of sensors such as ion selective electrodes and temperature sensors provide even more details about the composition of the sample and the accuracy of the analysis.  Standard CMOS processing is used to fabricate the instrumentation and post-processing is used to fabricate the sensors on the top surface of the same die.  Studies using this device hope to determine how pollutants are dispersed through atmospheric winds and deposited into natural waters.  This work is supported by the Engineering Research Centers Program of the U.S. National Science Foundation under Award No. EEC-9986866.