wouldn't it be fun to see a geodesic take on a new blobby shape, or see a robot that extended psuedopods and clambered around?
well, just take a geodesic sphere and replace the struts with telescoping sections like radio antennas, then in any direction it can bulge out and clamber around or just look nifty.
How small can it get, perhaps buckminsterfullerene like molecule linked with nested buckytube struts that are lined with electrically responsive liquid crystals could do it to make an EM electrically actuated nanorobot.
Hoberman sphere version available as well.-- beanangel, Oct 29 2019 56 nm gold nanoantennas https://www.ncbi.nl...rticles/PMC5026460/ [beanangel, Oct 31 2019] At a nanometre scale, how is the selective activation of the struts achieved ?-- 8th of 7, Oct 29 2019 Liquid crystal helices curl and uncurl in response to electricity, the nested tubes have C100-300 diameters giving them room to expand
The liquid crystals might have halogen groups or -OH attached to them to make them stickier-- beanangel, Oct 30 2019 Yes, but how exactly is the electricity directed to specific structural elements and not to others ?-- 8th of 7, Oct 30 2019 I'm with [8th]*. You could probably engineer some sort of sliding-filament mechanism, but getting control of independent elements will be difficult.
If I were going to do this, I'd probably use DNA - either as the structural+movement element, or just as the movement element. Imagine an extended telescoping rod, with a long piece (as long as the extended rod) of single-stranded DNA fixed to each end. If you now add a short piece of DNA whose ends are complementary to the two ends of the long piece, it will tend to anneal and thereby pull the two ends together, shortening the rod. Since there are almost infinitely many possible DNA sequences, you could achieve independent control of any number of rods by using different short DNAs in the solution.
[*In this one very specific matter.]-- MaxwellBuchanan, Oct 31 2019 Is there a magnetic type action? How much distance is in that annealing action?. I thought it was randomly bumping till very close.-- wjt, Oct 31 2019 Yes, that would be a problem. You'd probably have to have some sort of random movement, or temporary compression of all elements, to allow annealing of the short piece(s).
There are some proteins which will bind to a given sequence of DNA and bend or wrap it, to actively shorten it. But there's a finite number of such proteins and it would get messy.-- MaxwellBuchanan, Oct 31 2019 I thought it might work with gold nanoantennas. [link] shows them at 56 nm-- beanangel, Oct 31 2019 OK, that's a start.
If each element had a pair of antennae tuned to two different frequencies, and tightly resonant, then only the element receiving the correct frequency pair would respond. The system would need two narrow band frequency-agile transmitters as a driver.-- 8th of 7, Oct 31 2019 random, halfbakery