Towards the design of powerful and compact tactile displays

In minimally invasive surgery, tactile feedback is lacking. A tactile display, consisting of a matrix of micro-actuators, represents tactile sensations on the fingertip. Miniaturising powerful, dynamic and accurate actuators with a sufficient stroke and bandwidth is a considerable challenge. This paper discusses some design considerations of such a display and illustrates them with several prototypes. The first prototype presented below uses a shape memory alloy. Although it meets most requirements, the bandwidth is limited. The second prototype is based on a closed hydraulic circuit. Hydraulics are promising due to their potential for high power density. The last prototype is an open hydraulic system. This realisation is a very light, robust and simple display. The challenge moves to the design of a small proportional hydraulic valve.status: publishe