Molecules can be delivered through a tiny channel templated by one strand of DNA.
The developers are using this to deliver precise amounts of chemicals through the membrane of individual cells. This is highly cool, with all sorts of research implications. And eventually, perhaps therapeutic implications - they're talking about scaling it up to process 100,000 cells at a time.
So I got to wondering: If someone loaded up these reservoirs with two kinds of molecules, that would stick to each other but not to themselves, could this be used as an ink-jet printer at the nanoscale?
For starters, use one kind of molecule that will stick to a surface. Squirt it on and see if it worked. Then, scan the tip while you squirt.
Once you start using multiple kinds of molecules, you can perhaps build 3D structures. And with a patterned surface, it might be possible to get atomic precision.
With a million addressible reservoirs, and 10 ms per 1-nm voxel, it would be possible to build the volume of a human cell in a few hours.
Hat tip to Next Big Future.