PHYSICS AND TACTILE PERCEPTION OF FLUID-COVERED SURFACES

Little is known about the linkage between the physical properties of fluids and how they are perceived. Therefore, 15 fluids with diverse rheologies were characterized physically by three participants via a novel “force plate” (FP) device. Perceptual ratings were made by 20 participants, of 27 “sensory” attributes (e.g., oily) and 14 “emotional” attributes (e.g., arousing). Factor analyses decomposed 14 physical measures obtained from the FP into factors approximating friction, normal vibration, and tangential vibration; the sensory attributes into watery, textured, slick, silken and viscous factors; and the emotional attributes into factors labeled pleasant, sensual and harsh. Pleasant and harsh were related to textured and silken. Fluids perceived as more watery elicited greater normal and tangential vibration and less friction, whereas high viscous scores were associated with lower vibration factor scores and increasing friction. These results emphasize the complex perceptual nature of fluid-coated surfaces as compared with dry, solid surfaces. PRACTICAL APPLICATIONS In developing consumer products that are fluid-based (e.g., various foods or cosmetic preparations), it is desirable to reach an end goal in terms of how the fluid feels. This is achieved primarily by altering the physical composition of the fluid. The reported research established relationships between the percepts and physical composition of a diverse set of fluids. These relationships allow early insights concerning how one might formulate a product to produce a given, desirable, percept.