Bubble Driven Arrayed Actuator Device for a Tactile Display

We designed and made a micro meter sized arrayed actuator device for use in a tactile display. Each actuator uses a liquid-vapor phase change to drive a micro needle that stimulates receptors in a finger that is in contact with the array. The actuators consist of a flexible diaphragm structure and a bottom plate, which are bonded to create a cavity between them. A micro needle and a micro heater are formed on the diaphragm and the plate, respectively, of each actuator, and the sealed cavity that is thereby created is filled with an operating liquid. We manually assembled these components to form a 3times3 arrayed actuator device, 15times15times1 mm in size. Increasing the pressure in the cavity by activating the heater and generating bubbles, deformes the flexible membrane and drives the needle upwards. We experimentally evaluated the device and obtained a large needle displacement (61 mum) with 457-mJ input energy. This magnitude of displacement should easily stimulate receptors on the tips of fingers.