Post on 10-Oct-2020
Thermo-responsive Poly(Ionic Liquid) Valves for Microfluidic Devices
1
Alexandru Tudor, Janire Saez, Larisa Florea, Fernando Benito-Lopez and Dermot Diamond
The Origin of Ionic Liquids
2
Paul Walden (1863-1957)
1914
Ethylammonium Nitrate
Ionic Liquids
3
Common cations
Common anions
-
+
Ionic Liquid Monomers
4
Cationic Anionic
+ -
5
Tributylhexyl Phosphonium Sulfopropyl Acrylate (P4446-SPA)
Crosslinked Poly(Ionic liquid)s
Polypropylene Glycol Diacrylate
Crosslinker
Monomer
P4446-SPA
Photoinitiator
H2O + Acetonitrile
5 %m Crosslinker
3 mm
1 mm
~200 kLux for 30min
Poly (Ionic Liquid) Hydrogels
6
1 mm
7
10
11
12
13
14
15
16
17
0 5 10 15 20 25
Are
a (
mm
²)
Time (minutes)
1% w/w NaCl 1% w/w NaCl DI Water
1 mm
8
Temperature Responsive Poly(Ionic Liquid)s
+ -
-
-
-
-
-
-
-
+ + +
+ + + +
9
15
25
35
45
55
65
755
6
7
8
9
10
11
12
13
14
15
0 50 100 150 200 250
Te
mp
era
ture
(C
)
Are
a (
mm
²)
Time (min)
Heating Cooling Heating
1 mm
10
6
7
8
9
10
11
12
13
14
15
16
0 10 20 30 40 50 60 70 80 90
Are
a (
mm
²)
Time (min)
Swelling-Reswelling Cycle
20 oC
50 oC
11
Microfluidic Chip Fabrication
Inlet
Outlet
Gel
Chamber
Channel
Top view
From
20 oC to 50
oC
Side view
Syringe Pump Chip
Heater
Nanoflow meter 500 nL·min-1
20 oC to 50 oC
20 oC to 50 oC
0
20
40
60
80
100
120
140
160
0.00 200.00 400.00 600.00 800.00 1,000.00
Flo
w (
nL·m
in-1
)
Time (s)
12
50 °C 20 °C
Temperature-regulated Flow
Shrinking and Swelling Kinetics
13
0
20
40
60
80
100
120
140
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00
Flo
w (
nL
·min
-1)
Time (s)
0
20
40
60
80
100
120
140
160
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00
Flo
w (
nL
·min
-1)
Time (s)
Acknowledgements • Dr. Larisa Florea, Dr. Simon Gallagher,
Dr. Simon Coleman.
• Dr. Fernando Benito-Lopez, Janire Saez.
• Conor O’Quigley, Tom Glennon.
• Wayne Francis, Aishling Dunne, Danielle Bruen, Jennifer Deignan.
• John Burns, Joseph Hennesy.
• Prof. Dermot Diamond.
• Marie Curie ITN FP7 OrgBIO project.
14
Conclusions
• Thermo-responsive P4446-SPA hydrogels can be used as temperature-operated valves in microfluidic devices.
• Further investigate the possibilities of using the P4446-SPA hydrogels as flow regulators in microfluidic chips.
15
16
Valve shrinking kinetics
𝑦 =𝑎
1 + 𝑒𝑏+𝑐𝑥+ 𝑑
Where: a. the maximum value of the curve b. the intercept c. the slope d. the offset
17
Shrinking Swelling
Repetition C Repetition C
1 0,89 1 0,91
2 0,36 2 0,94
3 0,52 3 0,83
4 0,80 4 0,38
5 0,67 5 0,49
6 0,62 6
MEAN 0,64 MEAN 0,71
DESVEST 0,19 DESVEST 0,26
RSD (%) 29,80 RSD (%) 36,41
Rate constant calculation results
18
1 mm
Salt Concentration Induced Shrinking
19
10
11
12
13
14
15
16
17
0 5 10 15 20 25
Are
a (
mm
²)
Time (minutes)
1% w/w NaCl 1% w/w NaCl DI Water
20
1 mm
21
Temperature-induced Shrinking Kinetics
15
25
35
45
55
65
755
6
7
8
9
10
11
12
13
14
15
0 50 100 150 200 250
Te
mp
era
ture
(C
)
Are
a (
mm
²)
Time (min)
Heating Cooling Heating
22
0
20
40
60
80
100
120
140
160
0.00 5.00 10.00 15.00
Flo
w (
nL
·min
-1)
Time (s)
3
0
20
40
60
80
100
120
140
160
0.00 5.00 10.00 15.00
Flo
w (
nL
·min
-1)
Time (s)
5
0
20
40
60
80
100
120
140
160
0.00 5.00 10.00 15.00
Flo
w (
nL
·min
-1)
Time (s)
6
0
20
40
60
80
100
120
140
160
0.00 5.00 10.00 15.00
Flo
w (
nL
·min
-1)
Time (s)
4
0
20
40
60
80
100
120
140
160
0.00 5.00 10.00 15.00
Flo
w (
nL
·min
-1)
Time (s)
1
Valve Shrinking Kinetics
0
20
40
60
80
100
120
140
160
0.00 5.00 10.00 15.00
Flo
w (
nL
·min
-1)
Time (s)
2
23
0
20
40
60
80
100
120
140
0.00 5.00 10.00 15.00 20.00
Flo
w (
nL
·min
-1)
Time (s)
2
0
20
40
60
80
100
120
140
0.00 5.00 10.00 15.00 20.00
Flo
w (
nL
·min
-1)
Time (s)
3
0
50
100
150
0.00 5.00 10.00 15.00 20.00
Flo
w (
nL
·min
-1)
Time (s)
4
0
20
40
60
80
100
120
140
0.00 5.00 10.00 15.00 20.00
Flo
w (
nL
·min
-1)
Time (s)
5
Valve Swelling Kinetics
0
20
40
60
80
100
120
140
0.00 5.00 10.00 15.00 20.00
Flo
w (
nL·m
in-1
)
Time (s)
1