Powerful Acoustogeometric Streaming from Dynamic Geometric Nonlinearity

Past forms of acoustic streaming, named after their progenitors Eckart (1948), Schlichting (1932), and Rayleigh (1884), serve to describe fluid particle transport phenomena from the macro micro-scale. Governed by viscosity, traditional streaming arises second-order nonlinear coupling between fluid's density velocity, with first-order wave time averaging zero. We a form acoustogeometric that has nonzero contribution. Experimentally discovered in nanochannels height commensurate viscous penetration depth channel, it interactions surrounding channel deformation leading order pressure field, generating flow pressures three orders magnitude greater than any known acoustically mediated mechanism. It enables propulsion fluids against significant Laplace pressure, sufficient produce $6\text{ }\text{ }\mathrm{mm}/\mathrm{s}$ 130--150 nm tall nanoslit. find quantitative agreement theory experiment across variety conditions, identify maximum rate 1.59 times depth.