Enabling microsystems for monitoring cells
Pamela Abshire1, Elisabeth Smela2
1 Dept. of Electrical & Computer Engineering, Univ. of Maryland, College Park MD
2 Department of Mechanical Engineering, University of Maryland, College Park MD
group members: Jeff Burke, Marc Dandin,
Honghao Ji, Nicole Nelson, Somashekar Prakash,
David Sander, Anshu Sarje, Mario Urdaneta
CMOS Sensors
Microfluorometer = custom filter + low noise detector + LED
Thin film absorption filters, differential sensors for noise immunity
Microfluidic Systems
Sample preparation
Passive cell sorting:
deterministic lateral displacement
Active cell sorting:
dielectrophoresis
BTA in toluene
Sudan II in PDMS
Cell trapping
Microsystems
enable
manipulating and
monitoring
cells
Capacitance sensor
Surface coupling of adherent cells correlates with viability,
surface attachment, proliferation
adhesion
sedimentation
4 day
sensor
recording
sedimentation
Contact imaging
Detecting cells and particles in the near-field
image through microscope
contact image
superposition of image &
contact image
adhesion
Low light optical sensors
Ultra low dark current,
replacement for photomultiplier tubes
Thermally Generated Carriers
on the bench
with 16 µm beads
6
x 104
Trapping against a
microfabricated filter
3
2
1
0
-2
-20
0
20
40
60
80
Junction Bias (mV)
100
120
Antigencrosslinked
antibodies
Uncompensated Mismatch
Compensated Mismatch
160
Antigens
140
120
100
80
Antibodies
60
B cell with added
aequorin gene and
antibodies specific
to bioagent
40
20
-3
-40
Signal from B cells upon
introduction of stimulus
CANARY Cell
180
4
-4
IBI’s genetically
engineered B cells to
detect pathogens
Thermally Generated Carriers vs. Junction Bias (mV)
5
-1
in vitro with cells
on the chip
Dielectrophoresis
to trap cells in
microwell
Application: Cell-Based Pathogen Detection
Reporter cells trapped in microfluidic chamber,
bioluminesce when exposed to stimulant
compromised
cells
Number of Occurrences
cells healthy
& active
Cell trapping against
a monolith frit
Light emission
0
-0.025 -0.02 -0.015
-0.01 -0.005
0
0.005
0.01
0.015
0.02
Mismatch at -0.5 ms after reset (V)
0.025
Detector
Intellectual merit:
Broader impact:
Acknowledgements:
New ways to manipulate and monitor cells.
New applications enabled by handheld devices.
Benefits to society: health, safety, medicine,
commerce. Interdisciplinary education.
NSF Award IIS0515873 and MTech.
Maryland NanoCenter. Innovative Biosensors, Inc. (IBI)