Studying the dynamics of drying droplets using a graphene sensor

The evaporation of water droplets on graphene sensors, which are a non-conductive substrate made of silicon dioxide with graphene deposited on it, obtained by chemical vapor deposition, as well as copper electrodes deposited by magnetron method, is studied. It is shown that a water droplet deposited on the sensor surface changes its conductivity as it evaporates. The dependences of the resistance of the graphene sensor on the geometric characteristics of the droplet (height, contact angle, contact area of the droplet with the surface) are established. The sensitivity of the sensor to determining the evaporation mode of the droplet is demonstrated.