During the 5 and half years of COPMAT we have performed work along several fronts: theoretical, computational and experimental. For the sake of concreteness we shall refer to the specific workpackages.
WP1: We have explored the effects of near-contact interactions (NCI) on the global rheology of the soft-flowing material at the scale of the experiment, under a broad variety of conditions and regimes of motion. Invariably, the result was that the relative strength of the NCI versus capillary forces is the key control parameter dictating the large-scale rheology of the material. However, NCI need not been modeled down to the supramolecular scale (10 nm) but can be coarsed grained up to micrometric scale without appreciably affecting the material rheology. This finding is the cornerstone of COPMAT and largely responsible for its major success in describing a variety of soft-flowing regimes. In particular, it has relieved us from the extremely demanding task of performing local grid refinement, which would have been a major and very time-consuming ordeal.
WP2: We have developed leading-edge HPC codes (LBsoft and LBCUDA) which represent the state of the art in the field of colloidal bijels. LBCUDA can reach up to 100 GLUPS (hundred billion lattice updates per second) on moderately large GPU clusters, and even on smaller size computers it could allow the computational/experimental design of bijels materials under confinement.
WP3: We have performed very large scale simulations of a very peculiar trabecular-like media, the deep-sea sponge Euplectella-Aspergillum and highlighted the unsuspected role of hydrodynamics not only to relieve mechanical loads but also to facilitate selective feeding and sexual reproduction. This study has been published in Nature (July 2021), a very rare event for simulation-only work, and also made the object of several press-releases, including CORDIS, NSF as well as an article on Scientific American.
WP4: We have studied the motion of hierarchical emulsions (droplets within droplets) as well as of other new states of soft flowing matter, such as soft granular flows. These numerical studies have unveiled new regimes of motion and new functional regimes which have no counterpart in ordinary fluids. This work has been published in high-profile journals, such as Nature Communications (2021, 2023) and Physical Review Letters (2022). It lays the ground for future studies not only in soft material science but also in computational biology and micro/nanomedicine.
WP5: Our work has been systematically disseminated through the publication of over fifty high level international scientific journals, dozens of seminars and invited talks, over ten press-releases and also a few articles on magazines for the general audience. In addition, COPMAT work has received a dozen of distinctions, namely covers, highlights and Editorial picks. This work has also been exploited to obtain the ERC-PoC DROPTRACK, which was awarded to the PI in October 2022.
WP-Extra: In addition to the planned work, COPMAT has also delivered additional unplanned results in the following areas: 1) COVID-19 research: Computational studies of the COVID-19 spike dynamics (in the framework of a six-month extension due to COVID-19 disruption) ; 2) Active Matter: Dynamics of active droplets under confinement, 3) Machine-learning for microfluidics; development of a machine-learning based software for fast automatic droplet recognition and tracking in microflows. This is making the subject of the ERC-PoC (DROPTRACK).
