Leaf wetness duration (LWD) is an important measurement in agricultural meteorologysince it is a determining factor to pathogen infection and critical to the rate of plant disease development. Currently, there are commercially available electronic LWD sensors implemented in crop management systems, and, although, these sensors are robust and highly precise, they are unable to fully mimic the surface and wetting properties of real leaves. To mitigate the limitations of commercially available leaf wetness sensors (LWS), I developed a bio-mimetic sensor that closely replicates the surface properties and hydrophilicity of the leaves using a polydimethylsiloxane (PDMS) double-casting technique. Measurements taken from the modified LWS suggest that from three different leaf species, the commercialized LWS is capable of closely matching the wettability of only one of the corresponding leaves. This proof of concept shows that bio-mimetic leaf wetness sensors can better represent plant leaves and, therefore, not only verifies the commercialized LWS’s limited effectiveness but also demonstrates the importance of incorporating wettability into future LWS sensor development.