Faculty and students in the College of Engineering and the Biological Sciences Department in the College of Liberal Arts and Sciences-both of which emphasize experimental design and hands-on learning-collaborated on IMAPS. They designed the 4'x3'x1', 50-pound, laptop computer-operated boat to sample water parameters as part of environmental research and pollution monitoring.

The motor-driven IMAPS carries instruments that can measure water's temperature; depth; and pH, dissolved oxygen, nitrite, nitrate and ammonia levels and features a camera that can show what's below the water's surface. With a laptop and Internet, a nearby or far away user can guide the IMAPS via a GPS device and onboard camera to different parts of a water body.

That's an improvement over typical field sampling methods, which call for scientists to move in and out of water taking samples or travel from one spot to another via boat and then return the samples to a laboratory for analysis.

"IMAPS is very flexible. It can go into creeks, onto marshy surfaces and travel between tidal areas," said Dr. Courtney Richmond, associate professor of biological sciences.

Dr. Patricia Mosto, interim associate provost and former chair of the Biological Sciences Department, initiated the idea with Dr. Hong Zhang, assistant professor of electrical and computer engineering. Mosto said, "There is nothing like this for small bodies of water. Most devices are attached to buoys or are manually submersible. Generally scientists on boats move from location to location getting samples by hand. With IMAPS, you can be in your office and it can sample a lake for you."

"Although some current technologies provide a basic way to continuously observe fixed positions, their lack of crucial mobility and flexibility inspired our team to develop a robotic IMAPS device to monitor water pollution and study ecological conditions," Zhang said. "Our goal is to enable students from anywhere to retrieve data collected by a fleet of IMAPS deployed in various locations."

The team hopes one day to make the device available to others schools and researchers. "IMAPS is inexpensive to acquire and maintain while intuitive to operate. Many students, especially those at financially disadvantaged schools, can have unprecedented access to research equipment and be able to explore the wild or test water quality either (locally) or on a virtual field trip half world away." Zhang said. He said IMAPS also will be a convenient tool for local communities to use, enabling a greater number of people to easily monitor water pollution and pinpoint a polluting source.

To date, 11 students have worked with Zhang, Mosto, Richmond and Dr. Gina Tang, assistant professor of electrical and computer engineering, on the project for the last 20 months. The team received a provisional patent for IMAPS in the spring.

This semester students and their professors are working on IMAPS II, an amphibious device that will be able to travel between land and water on its own power. It will be used to work on creeks, marshes and other difficult terrains.

earlier related report
A Walk Along an Interface Yields Its Mobility
In the October 27th issue of Science (volume 314, page 632), researchers at Colorado School of Mines and Northeastern University report a novel computational methodology aimed at quantifying the kinetics of interfaces in diverse material systems. The paper, titled "Interface Mobility from Interface Random Walk", addresses computational issues in extracting interface kinetic parameters under experimentally relevant conditions. It is currently available online.

Interfaces are an important class of defects whose distribution affects the properties of the otherwise pristine material, both in nature and in technology. This is especially the case in polycrystals, thin films, multiphase materials, and composites, where the mechanical, chemical, and transport properties are sensitive to the underlying interfacial microstructure.

"In fact, tailoring this microstructure is an emerging paradigm for engineering high performance, multifunctional materials," said Zachary Trautt, a graduate student at Colorado School of Mines and the first author in the study.

The interfacial microstructure is subject to several driving forces during material synthesis and function. More often than not, these driving forces are large enough to cause the interfaces to move and the microstructure (or its precursor) evolves. Naturally, controlling the final microstructure requires accurate models that relate the interface motion to the driving forces in effect.

A quantitative measure of interface kinetics is the interface mobility, the ratio of the interface velocity to the driving force. Past studies on individual homophase crystalline interfaces (or grain boundaries) in several high-purity metals show an interesting trend; the experimental mobilities are orders of magnitude smaller than those extracted via computations. The discrepancy is often attributed to the presence of impurities, fueling speculation that even minute quantities of impurities significantly retard interface motion.

"An often overlooked fact is that computations are limited to tens of nanoseconds," said Moneesh Upmanyu, co-author and the lead researcher in the study. "As a result, they are performed at driving forces orders of magnitude greater than those commonly observed in experiments," he explained. "This further weakens the comparison, and there is a need to extend the computational studies to more realistic driving forces, and include the effect of impurities."

"Our computational methodology offers a way to address both these challenges, efficiently and with setups that are relatively simple," said Trautt.

The basis for the methodology is the pioneering theoretical work by Einstein, Smulochowski and Langevin on Brownian motion in the early 1900s.

"Just as their study related the dance of macroscopic particles to their diffusivity, the microscopic thermal fluctuations result in interface forces that conspire towards a one-dimensional dance of the average interface position, which in turn yields its mobility in the zero driving force limit," said Alain Karma, also a co-author in the study.

"The technique is remarkably efficient," noted Upmanyu. "The computations on pure aluminum yielded mobilities within a nanosecond, a significant savings in computational resources."

Comparisons with previous experiments and computations reveal that the retarding effect of impurities is much more severe than previously thought. The authors are now working on extending the theory and the computations to directly quantify the impurity drag effect.

Authors of the paper include Zachary Trautt, graduate student in Group for Simulation and Theory of Atomic-scale Material Phenomena (stAMP), Engineering Division, Colorado School of Mines; Moneesh Upmanyu, group leader of stAMP and Assistant Professor in the Engineering Division and Materials Science Program at Colorado School of Mines; Alain Karma, Distinguished Professor in the Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University. The study was funded by Department of Energy (BES, Dale Koelling), Department of Defense (ONR, Julie Christodoulou), and Alcoa Technical Center (Hasso Weiland).

Related Links
Rowan University
Northeastern
Colorado School of Mines
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All about the robots on Earth and beyond!