A method for mixing at least two fluids includes introducing the at least two fluids into a mixing chamber. The mixing chamber includes a piezoelectric component (500) for mechanical actuation of fluid motion within or adjacent the mixing chamber. The piezoelectric component includes at least first (400), second (410), third (420), and fourth (430) actuation domains, the first and third actuation domains being on first and third opposed sides of the piezoelectric component, and the second and fourth actuation domains being on second and fourth opposed sides of the piezoelectric component. The first and third domains are actuated at a first phase of a frequency of oscillation, and the second and fourth domains are actuated at a second phase of the frequency of oscillation.