High PZT-power actuation for the separation of polydisperse glycine crystals at high flow rates and solid content using acoustophoresis

Abstract

Acoustofluidics is a technique that can be used for particle separation purposes in both chemical and biological fields, with the technique appreciated for its capability of handling delicate material with no need for functionalization of particles/cells. Due to the generation of heat during the actuation of a ceramic piezoelectric element (PZT) and due to clogging, acoustofluidic separation is currently limited to dilute suspensions at a low flow rate. PZT actuation at a frequency that induces an acoustic standing wave drives the migration of particles toward the center of the channel. To overcome heating due to actuation at high power, a Peltier-based cooling system maintains the temperature of the PZT to a set point, keeping stable performance for up to a tested time of 24 min. Separation of suspensions of 10 wt.% and 5 wt.% of polydisperse glycine crystals in 5 v% methanol – ethanol buffer was achieved at a flow rate of 0.2 L/h. The cut-off found for the separation was 29.24±1.87μm and 19.51±1.19μm for 5 wt.% and 10 wt.%, respectively.