# Investigation of Vibration-Induced Transport of Newtonian and Non-Newtonian Fluids in Porous Media Using Lattice Boltzmann Method

## TL;DR

Vibration improves drug delivery by enhancing fluid spread and reducing shear stress in skin-like models.

## Contribution

This study reveals how vibration affects fluid transport and shear stress in drug delivery through porous media.

## Key findings

- Vibration increases wetted area by up to 21.3% for non-Newtonian fluids.
- Pressure cost per wetted area decreases with vibration for both Newtonian and non-Newtonian fluids.
- Vibration reshapes wall-shear history, reducing sustained shear exposure.

## Abstract

Pain and variable uptake remain practical barriers to needle-based delivery. Device-level vibration has emerged as a simple strategy for improving tolerability and dispersion, but its fluid-mechanical basis remains incomplete. Using a lattice Boltzmann model with a porous-media skin surrogate, we applied time-periodic inlet pressures at 0%, 16.6% (ΔP1), and 35.1% (ΔP2) amplitudes to Newtonian, model shear-thinning, and clinically measured protein formulations. We quantified the wall shear stress, wetted area, dispersion length, and pressure cost over one cycle. Vibration increased the normalized wetted area by 10.6% for Newtonian flow and by 15.9% and 21.3% for the non-Newtonian cases at
ΔP1
and ΔP2, respectively, while advancing the penetration front and lateral dispersion. The one-cycle pressure cost per wetted area decreased by 3.9% for Newtonian flow and by 5.96% and 7.80% for non-Newtonian flows. For shear-thinning fluids, the wall-shear history was reshaped, with a brief early amplification and late-phase mean reductions of 10.3% and 13.3% at
ΔP1
and ΔP2. These results establish a fluid-mechanical mechanism linking clinically relevant vibration amplitudes to reduced sustained shear exposure, deeper and broader depot formation, and improved conditions for drug uptake.