Title :
Flow control in microdevices using thermally responsive triblock copolymers
Author :
Stoeber, Boris ; Yang, Zhihao ; Liepmann, Dorian ; Muller, Susan J.
Author_Institution :
Dept. of Chem. Eng., Univ. of California, Berkeley, CA, USA
fDate :
4/1/2005 12:00:00 AM
Abstract :
Active and passive microflow control has been demonstrated using gel formation by dilute aqueous solutions of triblock copolymers at elevated temperatures. Solutions of a poly(ethylene oxide)106-poly(propylene oxide)70-poly(ethylene oxide)106 polymer, which has the trade name Pluronic® F127, have been used as a sample system. Flow in a microchannel has been stopped in less than 33 ms by introducing heat with an integrated electric heater. Viscous heating under high shear rates also induces gel formation, which has been used for passive automated flow control in a microchannel.
Keywords :
channel flow; electric heating; flow control; microfluidics; microvalves; polymer blends; polymer gels; 106 polymer; 106-polypropylene oxide; 70-polyethylene oxide; Pluronic F127; active microflow control; active microvalve; dilute aqueous solution; high shear rates; integrated electric heater; microchannel flow; microdevices; microfluidics; passive automated flow control; passive microflow control; polyethylene oxide; reversible gel formation; thermally responsive triblock copolymers; viscous heating; Actuators; Automatic control; Chemical engineering; Microchannel; Microfluidics; Microvalves; Polymers; Resistance heating; Temperature control; Valves; Active microvalve; microfluidics; passive microflow control; reversible gel formation;
Journal_Title :
Microelectromechanical Systems, Journal of
DOI :
10.1109/JMEMS.2004.839330
