1 Microfluidic components 2017

2 Contents Channels Filters Mixers Pumps Valves flow controlMicroreactors Surface microfluidics Droplet reactors PCR DNA chips flow control applications

3 Basic geometries:straight channel-separation channel -mixer -microreactor -...

4 Linear microreactor R.M. Tiggelaar et al. / Sensors and Actuators A 119 (2005) 196–205

5 Basic geometries: X,T,Y,HApplications: CE injectors mixers filters reactors

6 Particle filtering: H-filter

7 Catalytic microreactorYounes-Metzler et al: Applied Catalysis A: General 284 (2005) 5–10

8 Catalytic microreactor (2)Younes-Metzler et al: Applied Catalysis A: General 284 (2005) 5–10

9 Combine basic shapes to devicesInjector + separation channel precolumn reaction + separation post-column reaction

10 Meander-shapes Adv. Mater. 2012, DOI: 10.1002/adma.201203252D. M. Ratner, E. R. Murphy, M. Jhunjhunwala, D. A. Snyder, K. F. Jensen and P. H. Seeberger, Chem. Commun., 2005, 578

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12 Area needed: 6.3 mm * 6.3 mm

13 Pumps bubble pumps membrane pumps diffuser pumps rotary pumpselectrohydrodynamic electro-osmotic/electrophoretic ultrasonic pumps vacuum pumps

14 Pumps: actuation mechanism

15 Peristaltic pump = 3 valves in series

16 Pumps without moving partsSurface tension driven pump Electro-osmotic pump Nozzle-diffuser pump, Olsson, Stemme 1997

17 Osmotic pump

18 Thermal ink jet MEMS Handbook

19 Passive Active valves mechanical pneumatic geometric thermopneumatichydrophobic phase-change electrostatic piezoelectri thermal expansion

20 Membrane valve, pneumatic actuation

21 N=20 matrix chip to perform 400 independent PCR reactions, with in total 2860 in-line microvalves that was controlled by only two independent pneumatic pressure supplies. Liu J, Hansen C, Quake SR. Solving the ‘World-to-Chip’ interface problem with a microfluidic matrix. Anal Chem 2003a;75:4718–23.

22 Microvalves: Piezoelectric actuation, flap valveThermal expansion actuation, torsion valve

23 Geometric valves Pillar “forest” controls the rate of capillary flow.Rapid constriction of the flow channel will stop the flow. Side channel offers timing of flow. Transducers 2005, p. 1565

24 Fluidic diode in PDMS

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26 Microreactors Small volume good if expensive and/or dangerous chemicals Fast reactions because small diffusion distances Large surface area (either positive or negative effect) Good temperature control and fast ramp rates Good flow control because of laminar flow Besser: J. Vac. Sci. Technol. B 21.2., Mar/Apr 2003

27 Simple linear microreactorAnodic bonding: silicon and glass Heater electrode Nitride membrane Catalyst underneath Flow channel Bonded to glass wafer Microreactor dimensions Shin & Besser,

28 Cross-flow reactor in siliconFusion bonding: silicon-to-silicon

29 Electrowetting (EWOD)Hydrophobic coating Electrowetting: electrostatically induced reduction in the contact angle of an electrically conductive liquid droplet on an insulating hydrophobic surface.

30 Droplet movement

31 EWOD ≈ DMF ≈ Digital microfluidics

32 EWOD materials ITO = In:SnO2 transparent conductorParylene = CVD deposited polymer

33 DMF microreactor

34 PCR  DNA copy machine

35 PCR in SU-8

36 µPCR = rapid thermal ramping

37 Continuos flow PCR

38 Thermocycling PCR Angew. Chem. Int. Ed. 2007, 46, 1 – 5

39 Simple and complex devices1D devices – flow channels 1.5D devices – flow channels with junctions 2.x D devices – flat objects on surface (height << lateral dimension) 2.5D objects – height  lateral size; open top 3D objects – closed spaces (access holes)

40 Electronic vs. Fluidic planar (2D) 3Dsmall (cm2) anything (mm2 => 100 cm2) complex simple 109 elements few elements 15-30 litho steps 1-5 steps typical (13 highest so far) 1-10 $/cm2 highly variable few materials novel and exotic materials

41 Integration; component levelmany operations performed on a chip  increased automation, easier handling  smaller signals can be handled  less waste  different functions combined on chip

42 Integration: fluidicsfabrication yield low (as with early transistors) more difficult design (as with early ICs) no more jobs for analytical chemists (this was predicted for electronics engineers in 1960 !)