Lens cleaning via electrowetting

An apparatus, comprising:

• a mass detection circuit coupled to a surface covered with electrodes, wherein the mass detection circuit is configured to detect a first droplet present on the surface, and calculate a mass of the first droplet by measuring a change in capacitance between a consecutive pair of electrodes, and compare the mass of the first droplet with a first mass threshold value;
• a transducer circuit coupled to the surface, the transducer circuit including a transducer configured to excite a first vibration of the surface at a resonant frequency to form a high displacement region on the surface, wherein the transducer and surface form a lens unit, and wherein in response to a determination that the mass is greater than the first mass threshold value, the transducer circuit is further configured to excite a vibration at a first frequency of the surface to atomize the first droplet to generate a second droplet, the second droplet having a smaller volume than the volume of the first droplet;
• a voltage excitation circuit coupled to the electrodes and configured to detect the location of the second droplet, wherein in response to the detection of a mass and location of the second droplet, the voltage excitation circuit is configured to apply a sequence of differential voltages on one or more consecutive electrodes to move the second droplet to the high displacement region, and wherein in response to moving the second droplet, the transducer is further configured to excite a second vibration at a second frequency to atomize the second droplet to generate a third droplet, the third droplet having a smaller volume than the volume of the second droplet;
• and
• a memory circuit coupled to the transducer circuit, the mass detection circuit, and the voltage excitation circuit.