Apparatus with variable surface relief for conveying tactile or visual information has wax-filled cavities and heating elements under deformable membrane

摘要

The apparatus (10) consists of a series of sealed cavities (24) filled with a substance such as wax which varies in volume once a given temperature threshold has been passed. It has a deformable membrane (38) between the cavities and an outer surface (10a), and each cavity contains an electric heating element (26) to vary the volume of the enclosed substance. A variant of the design uses spring-loaded pistons instead of the deformable membrane to give a variation in the surface relief.