Principles of Electronic Nanobiosensors
Unit 2: Settling Time
Lecture 2.6: Beating the Limits – Droplet Evaporation
By Muhammad A. Alam
Professor of Electrical and Computer Engineering Purdue University
alam@purdue.edu
1
Outline
•Three approaches to beating the diffusion limit
•Droplet evaporation: theory
•Droplet evaporation: device fabrication
•Conclusion
Alam, Principles of Nanobiosensors, 2013
A ‘Mendeleev Table’ for bionsensors
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aM |
fM |
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pM |
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nM |
µM |
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mM |
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Alam, Principles of Nanobiosensors, 2013
Strategies to beat the diffusion limit
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τ ~ L2 |
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D |
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Fragment |
Reduce |
Generate |
the space |
the space |
locally |
Magnetic |
Droplet |
Ion torrent |
biobarcode |
evaporation |
approach |
All can achieve sub-fM detection in reasonable time |
4 |
Biomimetics:
Droplet on a leaf and coffee stain
W |
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L |
Lotus effect |
Coffee ring |
Alam, Principles of Nanobiosensors, 2013