Patent ID: 8349150

Claim:
An actuator comprising: a fixed body, comprising: a substrate; a plurality of electrodes disposed on a surface of the substrate at regular intervals along two orthogonal directions of the surface of the substrate, each of the plurality of electrodes having a planar shape; and an insulating layer disposed on the surface of the substrate and covering the plurality of electrodes; an electrically conductive liquid member, the liquid member being disposed on a surface of the insulating layer so as to provide a contact area where the liquid member contacts the surface of the insulating layer, wherein the contact area of the liquid member covers at least two adjacent electrodes in one of the two orthogonal directions; a movable body in contact with the liquid member and displaced from the insulating layer in a particular direction; a retaining device configured to adhere the liquid member to the movable body; a device configured to apply a first electrical potential and a second electrical potential to each of the plurality of electrodes; and a controller configured to vary liquid repellency of the insulating layer by controlling the device to apply the first electrical potential to a first number of electrodes from among the plurality of electrodes and to apply the second electrical potential to a second number of electrodes from among the plurality of electrodes, wherein the first number of electrodes is disposed adjacent to the second number of electrodes on the surface of the substrate, and wherein the controller is further configured to increase the contact area of the liquid member by increasing the first number of electrodes and decreasing the second number of electrodes and to decrease the contact area of the liquid member by decreasing the first number of electrodes and increasing the second number of electrodes.