Simple, low cost MHz-order acoustomicrofluidics using aluminium foil electrodes

It is now possible to circumvent costly and complex cleanroom fabrication procedures to produce MHz-order acoustically-driven microfluidic platforms through the use of electrode strips cut simply from kitchen aluminium foil and pressed against piezoelectric substrates. Cleanroom deposition, lithographic patterning, and etching are entirely avoided in favor of this cut-and-place technique, which enables the generation of acoustic Lamb waves of sufficient amplitude to demonstrate rapid and efficient microfluidic transport and manipulation, microcentrifugation, and even nebulization of both sessile drops and paper-based substrates. Elimination of microfabrication processes typical of acoustic microfluidics brings us a significant step closer towards commercially-viable consumer diagnostic devices, especially for use in the developing world.