Characterization of colloidal systems in a standalone PZT-glass capillary microfluidic ultrasonic tweezer

Abstract

This paper presents an acoustic PZT-glass capillary actuator mechanism for the characterization of colloidal systems. This actuator enables monitoring of the cumulative effect of the nanoscale force interactions between many individual nanoparticles at the millimeter scale which can be tracked by conventional optics. Since the actuation is through acoustical radiation and streaming forces, optical, dielectric or magnetic properties of the materials do not interfere with the actuation method, enabling accuracy in the measurements with applicability to a wide range of samples with different ionic concentrations. In this paper we show that the effect of the ionic charges on silica beads can be measured by collective squeezing and expansion of bead collections.