Sensor chip may provide economic irrigation management

A water sensor that's small enough to fit on a fingertip may provide growers with an economic way to better manage irrigation. Current moisture monitoring devices may be bulky and costly. But the silicon chip developed by Cornell University researchers could be mass produced for as little as $5 apiece. On top of the low price, it's 100 times more sensitive than current devices, according to a news release. The sensors use microfluidic technology developed by Abraham Stroock, associate professor of chemical and biomolecular engineering. The cavity is filled with water, and then the chip is inserted into a plant stem or into the soil.
Through a nanoporous membrane, it changes moisture with the environment and maintains an equilibrium pressure that the chip measures. Researchers are currently completing soil tests and may soon imbed the lab on a chip in the stems of grapevines.
By placing the sensors in vines, regulated deficit irrigation can be further refined. The practice places mild irrigation stress during specific times during the growing season to enhance berry characteristics. Already, the technology has grabbed the attention of such notables as Ernest & Julio Gallo Winery and Welch's juice company. The chip can be fitted with wires that are hooked up to a card for wireless data transmission. It's also compatible with existing data-loggers. Although chips may be left in place for years, they may break if temperatures drop below freezing.