Self-assembly due to capillary forces is a common method for generating 2D mesoscale structures from identical floating particles at the liquid-air interface . In a recent work, we show that different mesoscopic structures can be obtained using the magnetic Cheerios effect.
We show in our last paper , published in new Journal of Physics, that it is possible to create particle shapes with a low cost 3D printer, for composing specific mesoscopic structures. In fact, the capillary charge of an object can be controlled by its shape. Creating capillary multipoles allow us to program various structures.
We prove the concept for square, triangular and five-fold structures (see picture above). Since capillary interactions can be downscaled, our method, for producing capillary multipoles, opens new ways to low cost micro fabrication. We are now focussing our efforts to create complex and hierarchical structures. See also an article highlighting our work.
 J.A.Pelesko, Self-Assembly (Chapmann & Hall, Boca Raton, 2007)
 M.Poty, G.Lumay and N.Vandewalle, Customizing mesoscale self-assembly with 3D printing, New J. Phys. 6, 023013 (2014) – open access