Smiley face DNA
Congratulations!
In the answer for today's clue, the focus was on DNA origami.
The smiley faces (100 nm across) in this atomic force microscope image were made by DNA origami. Credit: Paul W. K. Rothemund -https://cen.acs.org/articles/90/i28/Just-Smiley-Face.html
DNA origami involves nanoscale folding of the DNA strands via custom DNA base pair strands. Due to the highly specific pairing interactions of DNA strands, only one type of pair possible for each base, the folding can interactions can be highly controlled and predicted. This is done initially on a computer program to predict the sequences necessary and then carried out experimentally.
Initially scientists used DNA origami as an art form to make art out of DNA strands into arbitrary shapes, testing and refining the technology and their control of it. Since then, the use of DNA origami has been proposed as a method delivering drugs and for nanorobots. As the shape can be specified in DNA origami, the DNA strands can be made to house popular drugs and help mitigate degradation of the drug while in transport!
This research has also began to spread into looking at proteins to see if the highly specified structure of proteins can be designs into specific shapes as well.