Autonomous flow regulation in a monolithic passive microvalve: Anisotropic design, fluid-structure interaction simulation and validation
Flow Measurement and Instrumentation, cilt.112, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 112
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.flowmeasinst.2026.103569
- Dergi Adı: Flow Measurement and Instrumentation
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Autonomous flow regulation, Fluid-structure interaction, Hydrodynamic anisotropy, Lab-on-a-chip, Passive microvalve, Soft lithography
- Akdeniz Üniversitesi Adresli: Evet
Özet
Precise fluidic control in portable Lab-on-a-Chip (LoC) platforms is frequently constrained by reliance on bulky, active pneumatic control systems. To overcome this limitation, a monolithic passive microfluidic valve was developed, computationally modeled and empirically validated for autonomous flow rate regulation driven by fluid-structure interactions (FSI). The device architecture, comprising a compliant poly(dimethylsiloxane) membrane and a rigid control chamber, was optimized via three-dimensional FSI numerical simulations and subsequently fabricated using a standard soft lithography and irreversible plasma bonding protocol. The hydrodynamic performance was characterized under static, dynamic square-wave and reverse pressurization regimes. Both numerical calculations and empirical evaluations confirmed that the pressure-induced downward deflection of the elastomeric membrane continuously modulates internal hydraulic resistance by geometrically constricting the fluidic pathway. During forward operation, the microvalve buffers pressure fluctuations, autonomously sustaining a stable volumetric flow rate of 53 ± 2.5 μL/min across a 40 to 70 kPa operational envelope with transient stability and minimal hysteresis. Conversely, backward flow testing revealed anisotropic behavior, functioning as a directional fluidic diode; reverse pressurization induces outward membrane deflection that deactivates the autoregulatory capability, resulting in unrestricted flow rates up to 70 μL/min at 100 kPa. By eliminating the need for external control hardware, this passive architecture provides a method for maintaining steady fluid delivery in microscale point-of-care diagnostics.