What is it about a cat鈥檚 fur that makes us want to stroke it, and how do you create a rubbery grip that you just can鈥檛 resist squeezing? An artificial finger that can gauge a raft of tactile characteristics for materials should help to find out.
Cathy Barnes and colleagues at the University of Leeds, UK, are . To get the measure of how rough or smooth a material is, they place a sample on a pressure-sensitive platform and allow an attached motor to 鈥渟troke鈥� the finger across it. Software then compares the sideways pressure that the platform feels with the sideways force applied to the finger. This gives a reading for friction or roughness.
At the same time, the software gauges how much downwards force the material absorbs by comparing the force applied by the finger with the force felt by the platform. Softer materials absorb more force. Meanwhile, a sensor at the finger鈥檚 tip measures temperature.
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The researchers plan to get volunteers to touch different materials and supply descriptions of what they feel to match the artificial finger鈥檚 data on the same materials. They hope to gather all the smoothness, softness and temperature measurements associated with a range of tactile sensations.
The team plans to use these to design packaging materials. 鈥淚ndustry knows a lot about the importance of the visual design of packaging but there鈥檚 a lack of understanding about the feel appeal,鈥� says Barnes, who is also a manager at the Faraday Packaging Partnership in Leeds. 鈥淚magine a carton of fruit juice that鈥檚 as soft as peach skin.鈥�
