Paper Number
DP11 My Program
Session
Dense Particulate Systems
Title
Viscosity metamaterials
Presentation Date and Time
October 14, 2024 (Monday) 5:25
Track / Room
Track 3 / Waterloo 5
Authors
- Cohen, Itai (Cornell University, Physics)
Author and Affiliation Lines
Itai Cohen
Physics, Cornell University, Ithaca, NY 14850
Speaker / Presenter
Cohen, Itai
Keywords
experimental methods; colloids; dense systems; future of rheology; particles; particualte systems; suspensions
Text of Abstract
Metamaterials are composite structures whose properties arise from a mesoscale organization of their constituents. Provided this organization occurs on scales smaller than the characteristic lengths associated with their response, it is often possible to design such materials to have properties that are otherwise impossible to achieve with conventional materials. Here, I will introduce and demonstrate a new material class-- viscosity metamaterials. To create these metamaterials we rapidly drive large viscosity oscillations in a shear-thickened fluid using acoustic perturbations with kHz to MHz frequencies. Because the time scale for these oscillations can be orders of magnitude smaller than the timescales associated with the global material flow, we can construct metamaterials whose resulting viscosity is a composite of the thickened, high-viscosity and dethickened, low viscosity states. Such viscosity metamaterials can be used to engineer a variety of unique properties including flow rectification, as well as negative, infinite, or zero effective viscosities – responses that are inconceivable with conventional fluids. The high degree of control over the resulting viscosity, the ease with which they can be accessed, and the variety of exotic properties achievable by viscosity metamaterials make them attractive for uses in technologies for which control over fluid flows and their instabilities are critical, ranging from coatings to cloaking to 3D printing.