Without realistic robot skin, robots will never have that humanlike personal touch, and will not have the degree of social acceptance that we all want robots to have.
"Touch is important in social interactions. Social touch are all those instances in which people touch each other, when shaking hands, when giving a pat in the back as a sign of congratulations and even in high-fives. Unless some form of alternative greetings are invented in the future, the typical social touches exchanged among humans may likely remain even with social robots...
Yet, one should not easily assume that humans will be comfortable with the idea of shaking an artificial hand made from a stiff material and can grip with a force that can reach up to 100 Newtons. In addition to the appropriate controls for a safe handshake grip and other forms of social touch, humanlike skin softness would be a reasonable requirement for the sociable robots envisioned to directly interact with humans in a social setting.
Human skin has properties that are not easy to replicate in synthetics. The authors of the paper identified three specific qualities that must be replicated to give that genuine human skin feeling:
The degree to which skin can be deformed by a force.
The degree to which the shape of skin conforms to an object that it touches or rests upon.
The difference between the way it deforms and then reforms - how force applied to skin is dissipated.
Yes, yes - I know what you're thinking. What about good old silicone and polyurethane? The authors test these simplistic skin substitutes and find them wanting. Take a look at their skin materials testing machine.