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A Dynamically Configurable Surface Based on Shape-Memory Alloy (Sma) Wires for Virtual Reality Applications
Published October 31, 1994 by ISATA - Dusseldorf Trade Fair in United Kingdom
Event: ISATA 1994
Virtual Environment (VE) technology is predominantly vision-based, a key missing feature being the feedback of tactile information. This makes it difficult to apply VE technology to those applications where the sense of touch predominates, such as assembly processes.
Consider the problem of feeling a virtual object whilst seeing the hand moving across it. The concept which is being adopted here is to immerse the operator in a traditional visual VE system complemented by a programmable array of tactels. The operator can reach out, touch and hapticly explore this real surface which is programmed to correspond to the virtual object seen in the helmet-mounted display.
Each tactel employs SMA wire to provide the basic actuation to a spring-loaded plunger. In another embodiment the SMA wire is connected to a flexible membrane which forms the top surface of a pressurized container. Feedback control is used in both cases to give continuous control of wire length. Surface displacements of 6 mm are obtainable from wire lengths of 150 mm.