This paper presents the research has been undertaken, to design and develop a micro actuator using electro rheological fluid technology, for visually impaired tactile display information technology, access applications. The micro actuator consists of a small cylinder made of ABS plastic material with 1.5 mm diameter and 10 mm long. The inner surface of the cylinder is coated by nickel using electroless coating process. A coaxial conducting rod of 1.02 mm diameter and 10 mm long is fitted vertically in the centre of the cylinder. The coated surface is used as first electrode and the coaxial conducting rod used as a second electrode, to form the micro actuation high voltage area. The microactuator structure has been used to develop a tactile display of a large scale in a matrix form of 124×4 actuators. An advanced software tools and embedded system based on voltage matrix manipulation has been developed to provide the display the near real time control. The new micro actuator development process, software control tools and actual developed prototype is presented in this paper. Prototype size 124×4 micro actuators, on a matrix form, with a separation distance of 2.54 mm, was manufactured. The experimental tests carried out into the prototype showed that each micro actuator was able to provide a vertical movement of 0.7 mm and a vertical holding force of 100 to 200mN. These results meet the necessary standard requirement of Braille applications. Stroke and dynamic response test showed the practicability of the developed micro actuator for electronic refreshable high resolution graphical tactile display, for visually impaired and blind information technology access applications.
A Soft Touch: Wearable Tactile Display of Softness Made of Electroactive Elastomers