Pressure-Free Surface-Induced Flow by Geometric Rectification

TL;DR

This paper introduces a novel pressure-free flow mechanism driven by geometric rectification of surface activity, revealing unique scaling laws and independence from viscosity, applicable across microfluidics and physiological systems.

Contribution

It presents a new theoretical framework for surface-induced flow as a pressure-free Stokes-transport mode, with a projection law linking source and geometry.

Findings

Flow exhibits inverted 'narrower-is-faster' scaling ($u\propto r^{-1}$).

Flow is largely independent of viscosity at leading order.

Flow rate scales linearly with length ($Q\propto L$).

Abstract

Pressure-driven flow collapses when confined ($u\propto r^{2}$). Asymmetry rectifies surface activity (exchange or slip gradients) into axial flux at $\Delta P=0$ despite zero net exchange. Lorentz reciprocity yields a projection law: throughput is the inner product of source with a geometry kernel. Signatures include inverted ``narrower-is-faster'' scaling ($u\propto r^{-1}$), leading-order viscosity independence, length amplification ($Q\propto L$), and linear superposition, defining surface-induced flow as a pressure-free Stokes-transport mode from microfluidics to physiology.