Vibrofluidic

Vibrofluidics is a field that uses mechanical vibrations to control and manipulate fluids and suspended particles within microfluidic systems. It integrates acoustics, fluid dynamics, and microfabrication to enable non-contact actuation, efficient mixing, pumping, droplet generation, and particle handling on small scales.

The core principles rely on acoustic waves interacting with fluids. Surface acoustic waves or bulk elastic waves generate pressure fields and streaming flows in microchannels. Acoustic radiation forces act on particles and droplets, guiding their positions, while acoustic streaming creates circulating flows that enhance mixing and transport. The combination of standing and traveling waves allows precise control of fluid interfaces, droplet formation, and cell or particle manipulation at Reynolds numbers where laminar flow dominates.

Common implementations use piezoelectric transducers, such as interdigital transducers on lithium niobate or other substrates, to produce surface acoustic waves that couple into a microfluidic channel. Other approaches employ bulk acoustic waves or integrated resonators. Vibrofluidic devices often rely on transparent channel materials like PDMS or glass to facilitate observation, while maintaining compatibility with biological samples.

Applications span rapid on-chip mixing and pumping, droplet-based microfluidics for digital microfluidics, sample preparation, and cell or particle handling. Vibrofluidics enables contactless sorting, focusing, and disruption-free manipulation, contributing to lab-on-a-chip platforms, biosensing, and diagnostic workflows. It offers advantages such as low mechanical wear, tunable actuation, and easy integration with existing microfluidic architectures, but challenges remain in heat generation, device complexity, and material compatibility for certain biological applications.