A new magneto rheological fluid based tactile display

A surface whose 3D form is computer controllable has long been the goal of many researchers. A wide variety of actuation methods have been tried previously, including: peizo-electric devices, shape memory alloys, electro-rheological (ER) fluids, miniature electric motors and many others. Many of these methods of actuation have inherent drawbacks and the ideal, economical, compact tactile array has not yet been constructed. In the tactile element constructed, an electromagnet effects a change in properties of a magneto-rheological (MR) fluid positioned between the actuating electromagnet and the user. Above the MR fluid is placed a non-ferromagnetic, impervious membrane, whose top surface forms the tactile surface for the fingers of the user to investigate. Experiments have been conducted to show the effect of various electrical inputs on the performance. The performance of the element has been characterised by investigating the tactile top surface with a force measuring probe. The paper reports a practical and effective way of achieving a tactile surface with a minimum of moving components.