Microfluidic components 2016 sami franssilaaalto fi Contents Pumping

Microfluidic components 2016 sami. franssila@aalto. fi

Contents • • Pumping Valving Dosing/dispensing Centrifugal fluidics • PCR • CE • Optofluidics flow control applications

Pumps • • bubble pumps membrane pumps diffuser pumps rotary pumps electrohydrodynamic electro-osmotic ultrasonic pumps vacuum pumps Only some of these scale beneficially into microscale !!

Membrane pumps: actuation

Pumps without moving parts Surface tension driven pump Electro-osmotic pump Nozzle-diffuser pump, Olsson, Stemme 1997

Osmotic pump

Passive • mechanical • geometric • hydrophobic Active valves pneumatic thermopneumatic phase-change electrostatic piezoelectri thermal expansion

Membrane valve, pneumatic actuation PDMS as flexible membrane Air in actuation channel, Liquid in fluidic channel. Air pressure deflects thin membrane against the wall of fludic channel. Why is it important that the fluidic channel is hemispherical ?

PDMS valve actuation http: //www. wormbook. org/chapters/www_microfluidics/microfluidics. html

How would this work ? http: //web. stanford. edu/group/foundry/Chip_Bonding. html

Cell stretch chip Zhang & Jiang, Lab Chip 2012 p 3441

PDMS flap valve (1) 3 -layer PDMS structure Thin central layer bends and opens and closes the valve.

PDMS flap valve (2) PMMA/PDMS valves and pumps for disposable microfluidics DOI: 10. 1039/B 907254 C

Peristaltic pump = 3 valves in series

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

Dosing/dispensing: ink jet MEMS Handbook

Electrospray nozzles

Electrospray nozzles

Microfluidic probe Juncker Delamarche Nature Materials 2005

In-channel dispensers Nguyen p.

PCR DNA copy machine

Thermal cycling Gold nanorod-facilitated localized heating of droplets in microfluidic chips Zhiyong Li, Pan Wang, Limin Tong, and Lei Zhang: Optics Express 2013

µPCR = rapid thermal ramping

Exponential amplification

Microfluidic PCR Silicon version:

Microfluidic PCR (2) SU-8 version:

Continuous flow PCR 3 contact temperature blocks Flow rate has been fixed so that the sample remains the right time in each temperature zone.

Electrophoresis chip with electrochemical detection

CE chip fabrication: channels in silicon (2)

CE chip fabrication: electrodes on polycarbonate (3) Lift-off

CE chip fabrication: electrodes on polycarbonate (4) Liftoff

Bond Si and PC to complete fabrication Polycarbonate Si

Optofluidics in PDMS One photomask !!

Optoelectrofluidics in silicon 13 photomasks required !!