A leaf sensor is a phytometric device (measurement of plant physiological processes) that measures water loss or the water deficit stress (WDS) in plants by real-time monitoring the moisture level in plant leaves. The first leaf sensor was developed by LeafSens, an Israeli company granted a US patent for a mechanical leaf thickness sensing device in 2001. LeafSen has made strides incorporating their leaf sensory technology into citrus orchards in Israel. A solid state smart leaf sensor technology was developed by the University of Colorado at Boulder for NASA in 2007. It was designed to help monitor and control agricultural water demand. AgriHouse received a National Science Foundation (NSF) STTR grant in conjunction with the University of Colorado to further develop the solid state leaf s