An Innovative Micro Actuator Using Electro Rheological Fluid Technology for Visually Impaired Tactile Display Information Technology Access Applications

Abstract

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.

An Innovative Tactile Interactive Interface Graphical Display for the Visually Impaired Information Technology Access Applications

“…An Oring of rubber has been used between the middle and the bottom plate to stop any oil leakage. Rubber sheeting elastic material was used as a membrane and this was selected to provide three functions for the micro actuator system [13][14][15][16]. These functions are: to insulate the ER fluid from the other parts of the system.…”

“…These are bulky ones, unless they use micro actuators, to control the flow, such as, actuators in Micro-Electro-Mechanical Systems (MEMS) technologies [2][3][4][5]. Pneumatic micro actuators that are based on Electro-Rheological (ER) fluid technology have great attention since the response of the ER fluid is fast, almost in msec, but the resolution and stroke are poor [8,11,[12][13][14]. The main phenomenon of the ER fluid is focused on the physics nature of the fluid and its natural sensation to change from one phase to another when an electric field is applied.…”

“…It is the electrostatic forces between particles that hold the structure together in a solid state. These forces are obviously dependent on the strength of the electric field applied [3,11,14]. Fricke J., 1996 has developed a display based on these fluids and has showed the possibility of improving the performance.…”

Characterization and Testing of an Electrorheological Fluid Valve for Control of ERF Actuators

“…The exotic property of ERF has many applications. Until now, most applications for ERF have only required low-torques, such as tactile sensing and haptic feedback [2][3][4][5][6][7][8]. Recently, researchers and the industry have been exploring ERFs for resistive applications [9][10][11][12][13][14][15][16][17].…”

“…Recently, researchers and the industry have been exploring ERFs for resistive applications [9][10][11][12][13][14][15][16][17]. In particular, recently, the research community has only performed ERF application studies on brakes [9], clutches [10], dampers [11,[13][14][15][16][17] and haptic devices [6][7][8]18]. However, a key missing capability is to use ERF as a torque-source actuator, which provides positive work on an external system.…”