From Cornell Chronicle article 2013-10-10:
Crop growers, wine grape and other fruit growers, food processors and even concrete makers all benefit from water sensors for accurate, steady and numerous moisture readings. But current sensors are large, may cost thousands of dollars and often must be read manually.
Now, Cornell researchers including Alan Lakso, professor in the Department of Horticulture, and PhD candidate Vinay Pagay, have developed a microfluidic water sensor within a fingertip-sized silicon chip that is a hundred times more sensitive than current devices. The researchers are now completing soil tests and will soon test their design in plants, embedding their “lab on a chip” in the stems of grape vines, for example. They hope to mass produce the sensors for as little as $5 each.