Shocking Colloidal Crystals
Dense colloidal suspensions can propagate and absorb large mechanical stresses, including impacts and shocks. In this work, the group of Prof. Lucio Isa in collaboration with scientists in the US and France, generated extreme localized deformations in colloidal crystals by exciting a target particle via pulsed-laser ablation. Stress propagation fronts take place, where fast-moving particles (V approximately a few meters per second) are aligned along the symmetry axes of the lattice.
These results demonstrate the accessibility of a regime where elastic collisions become relevant for suspensions of microscopic particles, behaving as “billiard balls” in a liquid, in analogy with regular packings of macroscopic spheres. These results indicate new design principles for shock-absorbing materials with a broad range of applications.
- Ivo Buttinoni, Jinwoong Cha, Wei-Hsun Lin, Stéphane Job, Chiara Daraio, Lucio Isa: Direct observation of impact propagation and absorption in dense colloidal monolayers. PNAS (2017) external page doi:10.1073/pnas.1712266114
- SNF press release: Liquid shock absorbers
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