Colloidal Active Carpets for Spatiotemporal Control over Microscopic Matter Transport

Active carpets, collection of active components on the surface, are ubiquitous in nature. Examples range from ciliary beds to sessile suspension feeders, generating cooperative hydrodynamic flows for nutrient capture. Even extracellular matrices dynamically regulate adhesion and sensing in real time. Emulating such behavior in synthetic systems offers transformative potential for lab-on-chip diagnostics, biosensing, and microparticle sorting. In this talk, I will present our work on synthetic active carpets, built using programmable dielectric matter. We show that dielectric colloids patterned on electrodes act as reconfigurable flow actuators under AC electric fields. By optically tuning the conductivity of the colloidal posts and designing their spatial arrangement on the electrode, we achieve spatiotemporally tunable electrokinetics for directed fluid transport. Our colloidal active carpets enable site-specific capture or release of diverse microparticles. Leveraging the universal electrokinetic response of microscopic particulate matter, we expect our platform to be broadly applicable for transporting microparticles like microplastics, bacteria, and vesicles.