Needle-type in-situ plant water content sensors with polyethersulfone membrane

Plant water content (PWC) strongly affects growth, yields and quality of the plants. In this paper we propose and demonstrate a needle-type PWC sensor with a polyethersulfone (PES) membrane. When the sensor is inserted into a plant, PES absorbs water from the plant according to its water content. The electric impedance of PES is determined by the amount of the absorbed water and reflects the PWC. The proposed sensor can explicitly measure the plant water content in-situ. The sensor was fabricated and characterized and successfully demonstrated an in-situ measurement of PWC of strawberry (Fragaria x ananassa).