A membraneless microfluidic MFC that uses laminar co-flow as a virtual separator, eliminating the membrane while maintaining electrochemical separation at the microscale. It enables highly compact bioelectrochemical devices for sensing, diagnostics, and micropower applications.
Alleinstellungsmerkmale
Eliminates the membrane bottleneck by using laminar co-flow as a virtual separator — cuts internal resistance by an order of magnitude while removing the most failure-prone component in classical MFCs.
Funktionsweise
Two miscible streams (anolyte with substrate-laden microbes, catholyte with oxidant) meet at a Y-junction and travel side-by-side through a microchannel at low Reynolds number. Diffusion broadening across the centerline is slow enough that the streams behave as separate half-cells while ions migrate freely between them, completing the circuit without a polymer membrane.
Leistungsbereich
Power density0.5–3 W/m² electrode area
Coulombic efficiency30–70%
Internal resistance50–500 Ω
Operating Reynolds number0.1–10
Stable run timeHours to days
Forschungsstand
Active research domain since the mid-2000s; TRL 4–5 with strong proof-of-concept demonstrations from groups at Stanford, Penn State, and KAIST. Main bottlenecks are biofilm management at low residence time and scale-up beyond single-channel devices.
Reaktorgeometrie
Y-junction PDMS or glass chip; channel 100–1000 µm wide × 50–500 µm deep × 10–50 mm long; thin-film carbon or Pt/C electrodes deposited along opposing channel walls; 2 inlets, 1 outlet.
Anwendungen
- Lab-on-chip biosensors and BOD probes
- Disposable point-of-care diagnostics
- High-throughput strain screening
- Educational and prototyping platforms
- Microfluidic toxicology assays
Aktives Volumen
10 µL – 0.5 mL
Limitiert durchη ≈ 130 mV
Ausgeglichen
Kein einzelner Widerstand dominiert – kinetische, ohmsche und Stofftransportbeiträge sind vergleichbar. In dieser Konfiguration ist das der günstigste Bereich für eine stabile Stromerzeugung.
Regime abgeleitet aus Tafel-η an der Anode + Elektrodenabstand + Monod-Anteil. Dieselbe Diagnose steuert die Farbe des Elektronenflusses live in der 3D-Szene.
Wichtige Parameter
Flow velocity0.1–10 mm/s
Channel width100 µm–2 mm
Re<2000
Mixing widthµm scale
Maßgebende PDEs
Navier–Stokes (incompressible, low-Re) for laminar co-flow; convection–diffusion–reaction for substrate, oxidant, and ionic species; Butler–Volmer kinetics at electrode boundaries; Monod kinetics for biofilm metabolism. Diffusion-broadening width δ ~ √(D·L/U) governs virtual-separator quality.