Making use of my amazing IT skills I have found more info
https://www.smarttirecompany.com/
sounds like NASA have used it to make tyres for the Mars missions - but for some reason the Mars missions didn't think they would need a bike
or at least that is one way to read it
still no mention of a rubber coating - although a picture of a MTB type tyre does seem to have the normal rubber knobbles
But if it moves and flexes maybe it does grip - although I can;t see it
addendum
The METL tire can last the life of your vehicle/bicycle, but eventually the rubber-like tread will wear down and can be re-treaded within our recycle system. It’s a lot better and cost-effective than having to buy a brand new set of tires.
looks like they technique involves a small amount of rubber and has good grip - according to them