# Dielectrocapillarity for exquisite control of fluids

## TL;DR

This paper introduces dielectrocapillarity, a method using electric field gradients to control fluid behavior in nanopores, with applications in energy storage and gas separation.

## Contribution

The paper introduces dielectrocapillarity as a novel mechanism for controlling polar fluids using electric field gradients.

## Key findings

- Dielectrophoretic coupling enables tunable control over liquid–gas phase transitions and capillary condensation.
- Electric field gradients enhance fluid uptake into nanoporous materials.
- Dielectrocapillarity links nanoscale effects to macroscopic dielectrowetting phenomena.

## Abstract

Spatially varying electric fields are prevalent throughout nature, such as in nanoporous materials and biological membranes, and technology, e.g, patterned electrodes and van der Waals heterostructures. While uniform fields cause free ions to migrate, for polar fluids they simply reorient the constituent molecules. In contrast, electric field gradients (EFGs) induce a dielectrophoretic force, offering fine control of polar fluids even in the absence of free charges. Despite their vast potential for optimizing fluid behavior, EFGs remain largely unexplored at the microscopic level due to the absence of a rigorous first-principles theory of electrostriction. By integrating state-of-the-art advances in liquid state theory and deep learning, we reveal how EFGs modulate fluid structure and capillarity. We demonstrate that dielectrophoretic coupling enables tunable control over the liquid–gas phase transition, capillary condensation, and fluid uptake into porous media. Our findings establish “dielectrocapillarity”—the use of EFGs to manipulate confined fluids—as a powerful mechanism for controlling volumetric capacity in nanopores, holding immense potential for energy storage, selective gas separation, and tunable hysteresis in neuromorphic nanofluidics. Furthermore, by linking nanoscale dielectrocapillarity to macroscopic dielectrowetting, we establish a foundation for field-controlled wetting and adsorption phenomena of polar fluids across length scales.

Electric field gradients (EFGs) have the potential to significantly influence fluid behavior in various natural and technological contexts, yet their effects on polar fluids at the microscopic level have been largely unexplored. This study introduces the concept of “dielectrocapillarity,” demonstrating that EFGs can be harnessed to finely control fluid structure, phase transitions, and capillary effects, thereby enhancing fluid uptake in nanoporous materials.