Rheological characterization and modeling of Laponite gels with application to snug-like locomotion

Abstract

Using various concentrations of Laponite, results were obtained on an AR1000 rheometer through various testing methods: stress sweep, creep tests, and large amplitude oscillatory shear tests, defined as LAOS. Concentrations of 1%, 2%, 2.5%, 3%, and 4% wt. of Laponite and distilled water solutions were tested. Laponite gels over 1% wt. concentrations were characterized as yield stress materials, as determined by stress sweep, creep test, and LAOS tests. The stress sweeps determined the yield stress, and the creep tests verified the results with a range of creep tests over and below the yield stress discovered in the stress sweep tests. The LAOS tests mapped a specific "fingerprint" of how the Laponite gel behaved on a Lissajous figure of stress and strain. These LAOS results are then fit with an evolution of deformation model in Matlab over various oscillation stresses. The results show that slug slime emulation is possible by altering the Laponite gel's properties with polymers to result in a slug slime equivalent for use in studying slug locomotion.