Proceedings of the National Academy of Sciences (PNAS), a peer reviewed journal of the National Academy of Sciences (NAS) - an authoritative
After 4 years of work, I've finally published my very first peer-reviewed theory paper: Design rules for controlling active topological defects
(and it's open access! :D)
I am sooo excited to finally be able to share this! I'll probably write some more in the future about what it was like to work on this project, but for now here's what I want to say about it:
I think this work is a beautiful example of how the long, meandering paths of curiosity-driven research can bring us in completely unexpected directions, yielding new ideas and technologies that might never have been found by problem- or profit-driven research.
We started this project because we were interested in the fundamental physics of active topological defects; we wanted to understand and develop a theory to explain their effective properties, interactions, and collective behaviors when they're hosted by a material whose activity is not constant throughout space and time.
Along the way, we accidentally stumbled into a completely new technique for controlling the flow of active 2D nematic fluids, by using symmetry principles to design activity patterns that can induce self-propulsion or rotation of defect cores. This ended up being such a big deal that we made it the focus of the paper, for a few reasons:
Topological defects represent a natural way to have discrete information in a continuous medium, so if we wanted to make a soft material capable of doing logical operations like a computer, controlling active defects might be a really good way of putting that together.
There have also been a number of biological systems that have been shown to have the symmetries of active nematics, with experiments showing that topological defects might play important roles in biological processes, like morphogenesis or cell extrusion in epithelia. If we could control these defects, we'd have unprecedented control over the biological processes themselves.
Right now the technique has only been demonstrated in simulations, but there are a number of experimental groups who are working on the kinds of materials that we might be able to try this in, so hopefully I'll get to see experimental verification someday soon!
