A deformable mirror based on electrocapillary actuation of a liquid surface

We propose and demonstrate a novel liquid based deformable mirror (LDM). The proposed LDM consists of an array of vertically oriented open capillary channels immersed in a pool of two immiscible liquids. A free-floating thin reflective membrane serves as the reflecting surface. By means of jet action, membrane deformation is induced. The control of jet flow through each channel is achieved by electrostatic means. This individual control enables the generation of complex surface profiles useful for adaptive optics applications. The advantages of this device include high stroke dynamic range, low power dissipation, high number of actuators, fast response time, and reduced fabrication cost. The device, however, can only be operated in a vertical orientation and is suitable for dynamic wavefront correction. A proof of principle of the device using an array of linearly addressed capillary channels is presented. Preliminary measurements showed that the response time is several milliseconds with a stroke of more than 10 microns. The design and fabrication of a prototype with around 100 actuators is in progress.