Droplet Mixing and Liquid Property Tracking Using an Electrodynamic Plate Resonator
Sprache des Titels:
Sensors, 2013 IEEE
Acoustic streaming in a sessile droplet can be
achieved, e.g., by surface acoustic wave transducers or piezoelec-
tric actuators. We present a novel method using a plate resonator,
which is electrodynamically actuated. The liquid droplet rests
on a round plate, which is suspended by spring structures and
oscillates in its own plane at a resonance frequency around 1 kHz.
The resonator loading depends on mass density and (complex)
viscosity of the liquid in the vicinity of the contact surface.
Actuating the oscillation at the resonance frequency yields high
displacement amplitudes, which consecutively leads to acoustic
streaming capable of effective stirring within the droplet. The
method is used to quantify the stability of two-phase systems
such as emulsions and suspensions. After a defined stirring
period, the resonator loading is measured every few seconds.
Resonance frequency shift and bandwidth are evaluated to derive
the viscosity of the liquid two-phase system and monitor the