"Electronic Tongue" Measures Food Flavors and Water Chemistry.

Using chemical sensors, University of Texas at Austin (UT) researchers have designed an electronic tongue that has the potential to distinguish between a dazzling array of subtle flavors. The electronic tongue assesses combinations of the four elements of taste: sweet, sour, salt, and bitter. In some ways, the electronic tongue has even outdone "Mother Nature"--it also can analyze the chemical composition of a substance. Although the researchers anticipate that the man-made tongue will largely be used to test food and beverage products, it also can diagnose the toxic chemicals in water supplies or the amount of wastewater present.

Collaborating on the research are Dean Neikirk of the Electrical and Computer Engineering Department and John McDevitt, Eric Anslyn, and Jason Shear of the Chemistry and Biochemistry Department.

The electronic tongue uses several different chemical sensors. These are attached to minute beads and placed on micro-machined wells in a silicon wafer. The wells mimic the many cavities of the human tongue, which hold chemical receptors known as taste buds. Each bead has a sensor that responds to a specific chemical by changing color. One sensor may turn yellow in response to high acidity and purple under base conditions. The researchers read the sensor results through an attached camera-on-a-chip connected to a computer. The sensors respond to different combinations of the four artificial taste elements with unique combinations of red, green, and blue, enabling the device to analyze several different chemical components simultaneously

Now that the silicon tongue has been developed, the team hopes to create a process for making artificial tongues more cheaply and quickly, For example, you could place such a tongue on a roll of tape, use it once, and throw it away. The researchers hope this technology will have environmental uses as well--especially in providing feedback and quantitative data on the precise chemical makeup of site-specific water and air resources. For details, telephone Dean Neikirk at [phone], send e-mail to [less than][e-mail][greater than], telephone John McDevitt at [phone], or send e-mail to [less than][e-mail][greater than].

Note: Ric Jensen heads up the Public Information Program for the Texas Water Resources Institute at Texas A&M University, Programs of the Institute are featured on the Web at [less than]http://twri.tamu.edu[greater than].

(Adapted with permission from New Waves, December 1998)