This shape, discovered by Dan Romik, is believed to be the largest (rigid) one that can move along a series of right-angled bends (in either left or right directions).
Although the double ended ‘sofa’ doesn’t contact every part of the walls’ surface, it would form an effective, low friction plug in an ultra low Reynold’s number flow regime.
Imagine a network of microfluidic channels engraved on a microchip. The channels carry fluids or tiny particles interspersed with accurately timed injections of Romik sofas.
This would allow stable packets of fluid to be moved around within rectilinear grids so that reactants between sofas could be delivered with great precision (or logic gates formed by interactions of streams).
The sofas, which would help keep flow channels clean by wiping (like a pipeline ‘pig’), could later be filtered out and reused.
