According to some US patent papers that I read can find many ways to refresh the braille cell. Below I put the links to that US patent papers. First link shows the US patent for Refresh-able braille cell display implemented with shape memory alloys. This refreshable braille display uses a single moving part per tactile element. This tactile elements formed from stainless steel tubing are assembled in densely arranged modules. This modules are positioned in a container. Shape memory alloy actuators are positioned in the tactile elements, isolated from any motion or flow in the pressurized medium. In this US patent describe a way to implement a braille cell display and if you want more information about that read the patent. https://patents.google.com/patent/US5685721 This link shows the US patent for Refresh-able braille cell display that braille cell provided with an actuator compromising a mechanically responding intrinsic conducting polymer. This actuators responds ...