Electrically Fueled Liquid-Liquid Phase Separation for Active Transport.

Out-of-equilibrium liquid-liquid phase separation (LLPS) of biomacromolecules in living cells creates membraneless organelle, enabling diverse functions including active transport. This has inspired the development of synthetic nonequilibrium LLPS systems; however, their active states are often hampered by waste accumulation, and their emergent functional properties remain largely unexplored. Here, we report an electrically fueled dissipative LLPS that sustains active coacervation without waste generation and, most notably, enables the recruitment and directional transport of molecules and nanoparticles via a new mechanism of active transport. By harnessing an electrochemical reaction network, we modulate a redox-sensitive peptide that rapidly triggers LLPS resulting in dynamic formation and dissipation of coacervates that suppress Ostwald ripening while exhibiting growth, fusion, and sustained homeostasis. The dissipative coacervates function as active carriers that recruit and transport diverse cargos-including organic molecules, biomolecules, and nanoparticles-with spatiotemporal control. Directional cargo transport arises from the interplay of active coacervation, cargo loading, Brownian motion in bulk solution, and spatially biased droplet dissipation and release near the cathode-a mechanism analogous to Brownian motors operating in cells. This work establishes a new paradigm for directional cargo transport via nonequilibrium LLPS, with broad implications for biotechnology, targeted delivery, and environmental remediation.