caa a22 4500 463235215 CHVBK 20180405153254.0 cr unu---uuuuu 170326e20070801xx s 000 0 eng 10.1007/s10404-006-0127-2 doi (NATIONALLICENCE)springer-10.1007/s10404-006-0127-2 Single-step replicable microfluidic check valve for rectifying and sensing low Reynolds number flow [Elektronische Daten] [J. Loverich, I. Kanno, H. Kotera] This paper presents a new microfluidic check valve well suited for low Reynolds number flow rate sensing, micropump flow rectification, and flow control in lab-on-a-chip devices. The valve uses coupling between fluid movement in a channel and an elastomeric column (flap) suspended in the fluid path to generate a strong anisotropic flow resistance. Soft lithography-based molding techniques were used to fabricate the valve, allowing for a low-cost, single-step fabrication process. Three valves—having heights of 25, 50, and 75μm, respectively—were fabricated and experimentally evaluated; the best of them demonstrated a maximum fluidic diodicity of 4.6 at a Reynolds number of 12.6 and a significant diodicity of 1.6 at the low Reynolds number of 0.7. The valve's notable low Reynolds number response was realized by adopting a design methodology that balances the stiffness of the elastomer flap and adhesion forces between the flap and its seat. A pair of elastomer check valves integrated with a miniature membrane actuator demonstrated a flow rectification efficiency of 29.8%. The valve's other notable features include a wide bandwidth response, the ability to admit particles without becoming jammed, and flow rate sensing capability based on optical flap displacement measurements. Springer-Verlag, 2006 Check valve nationallicence Microfluidic diode nationallicence Flow rectification nationallicence a : gap between the flap and the valve seat nationallicence b : valve seat width nationallicence c : flap clearance nationallicence δ : flap tip deflection nationallicence E : modulus of elasticity nationallicence h : channel height (depth) nationallicence I : second moment of area nationallicence l : length of the flap not in contact with the seat nationallicence L : flap length nationallicence ρ flap : flap density nationallicence ρ fluid : fluid density nationallicence Δ P block : valve blocking pressure nationallicence Δ P free : valve pressure drop in the free flow direction nationallicence Δ P flap : uniform pressure difference across the flap nationallicence Q : volume flow rate nationallicence t : flap thickness nationallicence μ : mass per unit length of the flap nationallicence U : strain energy nationallicence w 1 : channel width nationallicence w 2 : width of channel containing flap nationallicence w 3 : flap width nationallicence ω fluid : first natural frequency of the flap in a fluid nationallicence ω free : first natural frequency of the flap in free space nationallicence γ s : interfacial surface energy nationallicence Loverich J. Department of Micro Engineering, Yoshida-Honmachi, Sakyo-ku, 606-8501, Kyoto, Japan aut Kanno I. Department of Micro Engineering, Yoshida-Honmachi, Sakyo-ku, 606-8501, Kyoto, Japan aut Kotera H. Department of Micro Engineering, Yoshida-Honmachi, Sakyo-ku, 606-8501, Kyoto, Japan aut Microfluidics and Nanofluidics Springer-Verlag 3/4(2007-08-01), 427-435 1613-4982 3:4<427 2007 3 10404 https://doi.org/10.1007/s10404-006-0127-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10404-006-0127-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Loverich J. Department of Micro Engineering, Yoshida-Honmachi, Sakyo-ku, 606-8501, Kyoto, Japan aut NATIONALLICENCE 700 1- Kanno I. Department of Micro Engineering, Yoshida-Honmachi, Sakyo-ku, 606-8501, Kyoto, Japan aut NATIONALLICENCE 700 1- Kotera H. Department of Micro Engineering, Yoshida-Honmachi, Sakyo-ku, 606-8501, Kyoto, Japan aut NATIONALLICENCE 773 0- Microfluidics and Nanofluidics Springer-Verlag 3/4(2007-08-01), 427-435 1613-4982 3:4<427 2007 3 10404 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer