A Smartphone-Driven Acoustic Platform for Non-Invasive Modulation of Cellular Behavior in Microfluidic Channels

In recent years, passive cell manipulation in microfluidic devices has emerged as a crucial tool for biomedical and biotechnological applications, allowing control over cell positioning and behavior without the need for chemical labels or complex external forces. However, achieving precise and tunable modulation of cell dynamics remains a challenge, particularly with low-cost and non-invasive methods. In this work, we present a novel approach that leverages controlled acousto-mechanical perturbations (AMPs) to modulate cell arrangement and behavior in microchannels. By coupling a smartphone-driven audio speaker with a microfluidic device, acoustic signals are converted into mechanical vibrations of the tubing, generating AMPs that interact with hydrodynamically driven flows. Experiments with yeast cells and silica beads under different flow conditions revealed that acoustic stimulation induced periodic flow dynamics, with yeast cells showing tunable, flow-dependent responses while inert particles exhibited weak and stable modulation. Frequency-domain analysis highlighted a dominant response synchronized with the applied acoustic protocol, accompanied by higher-frequency components characteristic of acoustic actuation. These results demonstrate that simple, low-cost acoustic actuation revealed distinct dynamical responses between rigid inert particles and deformable biological cells and enable label-free cellular manipulation. The proposed platform offers a versatile, non-invasive, and accessible approach for controlled cell manipulation in microfluidics.