Skin is also incredible when you think about it. Each square cm is able to sense temperature, texture, whether it’s wet, sticky, etc. And it’s self healing. It’s hard to imagine robots getting very far without artificial skin.
Your point is entirely valid despite my critiques.
Technically, skin can't sense whether something is wet, and isn't particularly great at sensing temperature. Skin senses pressure and heat flow (derived via sensing temperature change of the flesh itself, rather than the temperature of the object it is touching), and perhaps can sense shear (there is a unique sensation when skin is stretched/pulled apart), as well as the weight of an object (if it is absorbent and more wet than damp). This distinction about what skin can directly sense manifests itself to deceive the human brain about wetness and temperature, specifically.
Wetness is a perception derived from feeling higher-than-expected heat loss and unusual pressure/sheer, and even through the sound made when squeezing an absorbent material or the sensation of water pooling around the finger (broadening the area of heat loss) when you squeeze into the material. Damp laundry at room temperature is perceived as obviously wet because it feels colder than it should if it were dry, but when we're pulling laundry out of a dryer we often can't tell if it's dry vs. still a bit damp -- the higher temperature of the object removes the sensation of heat flowing away from our fingers, so there's nothing our fingers can sense to tell us the clothes aren't dry until the clothes finally cool down to room temperature.
Our skin also doesn't sense the temperature of an object well if that object has a particularly high or low heat transfer coefficient of conduction. I recently bought a 6-pack of beer cans which have a moderately thick plastic vinyl label shrunk around the can. When I reach in my fridge, I can't convince myself to perceive it as chilled no matter how hard I try. Even though the vinyl is the same temperature as everything else in the fridge, it doesn't pull heat out of my finger tissue, so my brain cannot perceive that it isn't "room temperature". Conversely, picking up a normal metal can of beer that is just barely below room temperature, my brain perceives it to be much colder than it actually is because the metal draws heat away from my fingers so quickly compared to other objects. If wood is cooled 5 degrees below room temperature, it doesn't feel cold, but a can of beer certainly does!
It is absolutely incredible that our skin can sense things to such a high resolution that it seems like we have a lot more abilities than we actually have. It is also amazing how our brain integrates this into a rich perception. But there actually aren't many physical properties actually being measured, and this distinction matters sometimes for edge cases, some of which are quite common.
Skin can’t sense “wet” can it? I thought it was mostly just temperature, but also in combination with a few other properties you perceive it as moisture but it can be easily fooled because there’s not a direct sense for it.
