Marangoni forces created by surface plasmon decay.

We present optical microfluidic manipulation of silicone oil and glycerol via surface tension driven forces sustained by surface plasmon deexcitation energy. The phonon energy associated with the decaying optically excited surface plasmons in a thin gold foil creates thermal gradients capable of actuating fluid flows. Spectral dependence of the plasmon decay length and control of optical beam characteristics are shown to provide a means for further manipulation.