PHOTOTRANSISTOR BASED OPTOELECTRONIC TWEEZERS FOR CELLMANIPULATION IN HIGHLY CONDUCTIVE SOLUTION

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Transducer Eurosensors 07
PHOTOTRANSISTOR BASED OPTOELECTRONIC TWEEZERS FOR
CELLMANIPULATION IN HIGHLY CONDUCTIVE SOLUTION
H. Y. Hsu, A. T. Ohta, P. Y. Chiou, A. Jamshidi,
andM. C.Wu Berkeley Sensor and Actuator Center
and Dept. of Elec. Engineering and Computer
Sciences Berkeley, California, USA
ReporterTzu-Yu Chao
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Outline
Introduction Principle Fabrication Method Result C
onclusion
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Introduction
Cell manipulation technique Electrode-based
dielectrophoresis (DEP) high throughput
lack the flexibility of optical control Optic
Tweezers high resolution and flexibility
limited manipulation area Optoelectronic
tweezers (OET) utilized optically-induced
dielectrophresis flexibility of optical
control increase parallel manipulation
capability
REF Strategies for dielectrophoretic separation
in laboratory-on-a-chip systems University of
Surrey, Guildford, United Kingdom
REF Observation of a single-beam gradient force
optical trap for dielectric particles A. Ashkin
et. al. , Holmdel, New Jersey 07733
REF Massively parallel manipulation of single
cells and microparticles using optical images Pei
Yu Chiou, et. al. University of California at
Berkeley, USA. Nature Letter
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Principle
OET Use amorphous silicon as photoconductor
gtneed use low conductivity medium material
gtreduce cell viability
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Phototransistor Model
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Photoconductor (Amorphous Silicon) Required
light intensity gt 50W/cm2 Phototransistor Requ
ired light intensity lt 0.3W/cm2
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Fabrication
2µm-wide trenches
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Method
Light source 658nm Diode Laser
Applying a sinusoidal AC source with frequency
of 9MHz
Manipulation object Hela cell (cancer
cell) Jurkat cell (T cell)
Solution Phosphate-buffered saline
(PBS) Dulbeccos modified eagle medium (DMEM)
both solutions have the same conductivity 1.5 S/m
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Result
Light pattern area 250 µm x 50 µm
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Conclusion
1.Developed for operations in highly-conductive
solution 2.Required a much lower optical
intensity for operation
Reference
1 A. Ashkin, J. M. Dziedzic, J. E. Bjorkholm,
and S. Chu, "Observation Of A Single-Beam
Gradient Force Optical Trap For Dielectric
Particles," Optics Letters, vol. 11, pp. 288-290,
1986. 2 M. P. Hughes, "Strategies for
dielectrophoretic separation in
laboratory-on-a-chip systems," Electrophoresis,
vol. 23, pp. 2569-2582, 2002. 3 P. Y. Chiou, A.
T. Ohta, and M. C. Wu, "Massively parallel
manipulation of single cells and microparticles
using optical images," Nature, vol. 436, pp.
370-372, 2005. 4 A. T. Ohta, C. Pei-Yu, A.
Jamshidi, H. Hsan-Yin, M. C. Wu, H. L. Phan, S.
W. Sherwood, J. M. Yang, and A. N. K. Lau,
"Spatial cell discrimination using optoelectronic
tweezers, presented at 2006 Digest of the LEOS
Summer Topical Meetings (IEEE Cat. No.
06TH8863C). IEEE. 2006, pp. 23-4. Piscataway, NJ,
USA.