Edwin L. Aguirre
Waste products from mining and industrial manufacturing as well as heavy use of pesticides have resulted in the accumulation of toxic heavy metals
— such as arsenic, mercury and lead — in the soil and groundwater in many cities and farms across the country. Long-term exposure to these heavy metals through direct contact or the food supply has been linked to health problems involving the skin, kidneys, liver and the gastrointestinal and central nervous systems.
“Detecting and identifying these contaminants below the ground is a challenging task,” says civil and environmental engineering Prof. Pradeep Kurup
. “Traditional methods involve core drilling and sampling in the field, followed by analysis in the lab. These methods are time-consuming, laborious and expensive. They also expose personnel to contaminated materials.”
Kurup and plastics engineering Assoc. Prof. Ramaswamy Nagarajan
are conducting pioneering research to develop an electronic “tongue” for detecting and analyzing heavy metals on-site and in real time.
The tongue mimics the human gustatory system using an array of highly sensitive microelectrode sensors coupled with artificial intelligence. It is designed to “taste” soil and water samples and to detect — and identify — any heavy metals present. In addition to arsenic, mercury and lead, the sensors can detect trace levels of cadmium, copper, chromium, manganese, nickel, selenium, thallium and zinc.
Funding for the research is provided through a three-year $422,000 grant from the National Science Foundation. Kurup is the principal investigator (PI) for the project while Nagarajan is the co-PI.
A Taste for Sensing Danger
“Our electronic tongue will be simpler, faster, safer and more cost-effective compared with the traditional methods,” says Kurup. “Characterizing a contaminated site often accounts for approximately a third of the total cost of cleanup. The electronic tongue should cut the cost associated with field sampling and lab analysis by more than 50 percent.”
He says this technology will limit the exposure of lab personnel to contaminated soil and water by avoiding the need for drilling and collecting samples. Since site investigators will get the test results more quickly, they can provide state and federal regulatory agencies with critical information needed for taking appropriate actions, such as issuing drinking-water advisories to the public in a timely manner.
The technology can also be expanded to detect other types of toxins, making this approach applicable to diverse fields such as biotechnology, pharmaceuticals and medical diagnostics, the food industry, environmental monitoring, law enforcement and homeland security, he says.
Other members of the research team include Ph.D. candidates Barbara Deschamp (biomedical engineering and biotechnology) and Timothy Ponrathnam (plastics engineering), graduate students Seth Robertson and Maria Vidal (both civil and environmental engineering) and postdoctoral researcher JungHwan Cho.