Colour-forming materials, contact recording devices and pressure recording devices

Abstract

The present invention relates to devices and apparatus for detecting contact and optionally its duration and/or recording the level of pressure and/or its duration and/or recording the level of shear force and/or its duration. In particular, certain embodiments of the present invention relate to devices which comprise an element comprising a hydrophobic material and a color-forming material dispersed in at least a portion of the hydrophobic material. Certain embodiments of the present invention relates to materials comprising a solid dispersion of a color-forming material in an elastomeric hydrophobic material. The solid dispersion may take the form of a molecular dispersion or a partial molecular dispersion. Also included in the present invention, although not exclusively, are devices which comprise a hydrophobic material, a color-forming material and a color developing material wherein the color forming material and the color developing material are brought into contact when pressure of a predetermined threshold level is applied or removed from the device.

Dependencies are inferred from the claim text.