Yes, the famous smooth chair in daycare. This blue plastic chair always had a heavy static buildup and would painfully shock you no matter how many times it was discharged. The chair's texture was rubbed smooth from years or decades of kids sitting in it. I think they threw it out after a while because it was cruel to use it as the timeout chair. https://imgur.com/rn54n2Q
I didn't realize how deep an impact this chair had on me until I saw these chairs at my daughter's daycare. When I had to move one, I instinctively avoided the metal, including the two evil metal buttons on the seat back. I remember as a kid, I learned to make sure I maintained contact with a metal part as I got up by holding onto one of the legs.
> Among all the parameters they investigated, only one provided any hint at all: they spotted discrete changes in the materials' surface roughness at the nanoscopic scale.
> More concretely, they showed that contacts smoothed the tiniest bumps on a material's surface. How this causes contact electrification the team does not know, but as it is the only change they could detect, it is highly suggestive.
That suggests future experiments require some way to supply samples with where their surfaces (not just their charge) are in a known starting state. I'd say "just grind it down", but whatever you're grinding with also needs to have a standard state.
Perhaps something where a grinding/smoothing material is melted and then re-solidified between uses?
The article suggests that the important features are nano-scale things, like the "grain" of the molecules that comprise the surface, versus whether the surface is concave/convex/flat on a larger scale.
I wonder if portions of a thin ribbon of float glass could be useful, if the ribbon is consistently and continuously removed from the molten metal in a way that protects the bottom surface.
After 200 contacts they detected persisting tribological electrical series ranking, but then found surface roughness changes too. So.. it's correlation heading to a theory of causation.
Yes, the famous smooth chair in daycare. This blue plastic chair always had a heavy static buildup and would painfully shock you no matter how many times it was discharged. The chair's texture was rubbed smooth from years or decades of kids sitting in it. I think they threw it out after a while because it was cruel to use it as the timeout chair. https://imgur.com/rn54n2Q
I didn't realize how deep an impact this chair had on me until I saw these chairs at my daughter's daycare. When I had to move one, I instinctively avoided the metal, including the two evil metal buttons on the seat back. I remember as a kid, I learned to make sure I maintained contact with a metal part as I got up by holding onto one of the legs.
Ah my high school had those in yellow. What pieces of shit lol
> Among all the parameters they investigated, only one provided any hint at all: they spotted discrete changes in the materials' surface roughness at the nanoscopic scale.
> More concretely, they showed that contacts smoothed the tiniest bumps on a material's surface. How this causes contact electrification the team does not know, but as it is the only change they could detect, it is highly suggestive.
That suggests future experiments require some way to supply samples with where their surfaces (not just their charge) are in a known starting state. I'd say "just grind it down", but whatever you're grinding with also needs to have a standard state.
Perhaps something where a grinding/smoothing material is melted and then re-solidified between uses?
>> whatever you're grinding with also needs to have a standard state.
Yes and no. There are techniques for grinding three rough surfaces into three flat surfaces without a flat starter.
https://ericweinhoffer.com/blog/2017/7/30/the-whitworth-thre...
The article suggests that the important features are nano-scale things, like the "grain" of the molecules that comprise the surface, versus whether the surface is concave/convex/flat on a larger scale.
I wonder if portions of a thin ribbon of float glass could be useful, if the ribbon is consistently and continuously removed from the molten metal in a way that protects the bottom surface.
Did they just discover what every cat owner already knows?
After 200 contacts they detected persisting tribological electrical series ranking, but then found surface roughness changes too. So.. it's correlation heading to a theory of causation.