3 ms·
> Among all the parameters they investigated, only one provided any hint at all: they spotted discrete changes in the materials' surface roughness at the nanosc
by Terr_ 2y ago
> 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?
- sandworm101 2y ago>> 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.
- sandworm101 2y agohttps://ericweinhoffer.com/blog/2017/7/30/the-whitworth-three-plates-method https://ericweinhoffer.com/blog/2017/7/30/the-whitworth-thre...
- Terr_ 2y agoThe 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.