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Interacting colloids on a deformable medium
S. Dharmavaram, L.E. Perotti (2020)
Systems of interacting colloidal particles can be used to study problems in softmatter, membrane biophysics, and material design. Usually these particle systems are modeled on rigid surfaces due to the challenges in simulating the interplay between colloids and a deformable substrate. However, this restricts the study and design space of colloidal/membrane systems. To overcome this limitation, we have developed a new computational method where the particles positions are parameterized in the reference configuration using a pull-back operator. This allows the particles to move freely on a flexible substrate without the need of additional constraints. We have applied our newly developed approach to the study of colloidal packing on a deformable liquid surface, where different symmetric states are accessible as a function of the substrate bending stiffness. More information about this project can be found here.
Virus Kirigami and the Caspar-Klug Construction
L.E. Perotti, K. Zhang, J.Rudnick, R.F. Bruinsma (2019)
Inspired by the shape and maturation of the Acidianus two-tailed archaeal virus (ATV), we extended the classic Caspar-Klug construction for spherical viruses to include capsids with negative Gauss curvature. Introducing five- and seven- folds defects in an otherwise regular hexagonal lattice allowed us to systematically recreate the ATV geometry with different size and smoothness for the central body and tails. Combining this extended Caspar-Klug construction with thin shell elasticity theory, we explored how to codify the shape changes occurring during the ATV tails growth as a function of material properties and a modified Föppl–von Kármán number. More information about this project can be found here.
Extended Caspar-Klug construction to include capsids with negative Gauss curvature (left) and shape changes occurring during the ATV tails growth as a function of a modified Föppl–von Kármán number (right).