Sensors employing control systems determining locations of movable droplets within passageways, and related methods are disclosed. A sensor includes a movable droplet within a passageway supported on a substrate. The droplet may move to and from a quiescent point in the passageway which is at least partially formed by a hydrophobic layer. By including a hydrophobic layer having a hydrophobicity characteristic which decreases according to distance from the quiescent point, the droplet may move to a displacement position outside of the quiescent point in response to an external force. A control system of the sensor determines an acceleration and/or angular position of the sensor based on the displacement position. In this manner, a low cost sensor may be fabricated with without expensive nanostructures.