bacteria actuation, sensing, and transport (bast) in micro/nanoscale
DESCRIPTION
Bacteria Actuation, Sensing, and Transport (BAST) in Micro/Nanoscale. Dr. MinJun Kim Dept. of Mechanical Engineering & Mechanics Drexel University. Layout of This Presentation. 1. Introduction of Flagellated Bacteria. - PowerPoint PPT PresentationTRANSCRIPT
Bacteria Actuation, Sensing, and Transport (BAST) in
Micro/Nanoscale
Dr. MinJun Kim
Dept. of Mechanical Engineering & Mechanics
Drexel University
Layout of This Presentation
2. Microscale Bacterial Actuation - Chaotic Microfluidic Mixing System- Chemotactic Bacterial Sensing System- Self-sustained Microfluidic Pump- Autonomous Bacterial Transportation System
4. Microbial Risk Assessment
- Ultra-fast Bacteria Detection and Configuration- Rapid Bacteria Cell Lysis
1. Introduction of Flagellated Bacteria
5. Conclusions & Acknowledgements
3. Nanoscale Bacterial Actuation - Nanoscale Mechanical Actuator- Flagella-templated Nantube
Going Micro & Nano: Miniaturization Theory
Why do we need it?
- Reduced fabrication cost
- Reduced sample consumption
- High sample throughput
- Superior performance (speed / efficiency)
- MEMS and NEMS compatible
What are the applications?
- Molecular separations
- Chemical and biological synthesis
- Medical and clinical diagnostics
- Environmental monitoring
- DNA sequence analysis
- Process control
Why not use “nature”?
- Challenge to micron-nano scale actuation
- Intergration Engineering with Biology
Self-powered Bacterial Pump
Flagellated Bacteria (E.coli & Serratia marcescens)
Flagellated Bacteria:- Cell body & Flagella- Rod-shaped cell body : 2 m long, 1 m diameter- Flagella : rotary motor, hook, and filament
10 m
2 m
1m
A cell of E. coli, fluorescently labeled.(Turner, Ryu, and Berg 2000)
http://www.npn.jst.go.jp/ Namba
E.coli Rotary Motor, Hook, and Filament
25 nm
Filament – typically about 10 m and 20 nm in diameter. Helical shape in the unstressed state.
Hook – about 50 nm long and 20 nm in diameter. Plays the universal joint.
Motor – proton (H+) is the energy source. The typical rotation speed is about 100 Hz. The motor can rotate either direction.
Schematic diagram (Berg, 2003), electron micro-scopy image of the flagella motor (De Rosier, 1998), and http://www.npn.jst.go.jp/Namba
E.coli in Motion
Sequence of E. coli flagella bundling(Turner, Ryu, and Berg, 2000)
E. coli swim by rotating helical filaments. Filaments form a bundle and disperse the
bundle. Tumbles and runs change the swimming
directions.
Macro-scale Model of Bacterial Flagellar Bundling
Model Full-Scale
Fluid 10 5 cP 1cP
Flagella: 10 cm 10 um
Rotation: 0.3 Hz100 Hz
SetupTwo stepper motors.Epoxy-filled plastic tubes in helical shape.High viscosity silicone oil (100,000 cp).
Match geometryPitch, Aspect ratio, Number of turns.
Match flow characteristicsReynolds number 10-3 (Re 10-5 for Bacteria).
[ FRONT VIEW ] [ SIDE VIEW ]
Flow by Bundles Helices
- Flexible Helices Movie (Real time)
- Complex flow field induced by bundling
- Bundled state resembles single helix
flow
~
Bundled helices Double thickness helix
Test Geometry & Experimental Setup
y
x24 mm 20 mm 16 mm 12 mm 8 mm 4 mm 0.5 mm
Fluorescence
No Fluorescence
Width = 200 m
Depth = 40 m
(a)
(b)
• PDMS Microchannels Using Soft-Lithography Techniques
• E.coli: Tumbly (RP 1616), Wild type (HCB 33), and Immobile
• Concentrations of E. Coli: 0 ~ 109 /ml
• Flowrate: 0.5 ~ 1.25 l/min
• Velocity: 1 ~ 2 mm/s
(a) Buffer + 0.02% of FITC + Dextran (MW=77,000) 0.97 cp @ 24.3 C
(b) Buffer + 0.02% of Dextran (MW=68,800) 0.98 cp @ 24.3 C
Bacteria-Enhanced Diffusion
<Baseline> <Immobile E.coli>
<Tumbly E.coli> <Wild type E.coli>
Fixed at
U = 1.04 mm/s
x = 24 mm.
Each Concentration of E.coli = 1.05 109/ml. channel wall
Flow
Chemotactic Bacteria-Sensors
1
7
6
5
4
3
2
y
x
1.
3.
5.
7.
1
2
3
Bacteria’s Chemotatic Receptors
Sudden Change
Rotary Motor Performance Affected
Global Microfluidic Effects
Monitoring or Detecting
Bio-Sensor
Controlled-Mixing in Microfluidics
Formation of Bacterial Carpets
• Concentration of Serratia Marcescens
: 2 ~ 5 109/ml
• Time : ~ 1 hour
• Flow rate : 0.06 l/min
On : 10 seconds
Off : 5 minutes repeatedly
Flow
…etc…
…etc…
Glass wall
PDMS wall
15 m
Fill
fa
cto
r [%
]
Time [s]10
010
110
210
310
410
0
101
102
PDMSGlass
17 6 5 4 3 2
y
x
2
1
3
1
23
MJ Kim and KS Breuer, PNAS, 2007
Cell Orientation on Bacterial Carpets
-100 -50 0 50 1000
0.002
0.004
0.006
0.008
0.01
0.012
PD
FCell Orientation [Degree]
-30 < degree < 30 : 54.9013%
-40 < degree < 40 : 64.3485%
-50 < degree < 50 : 74.5086%
Single Cell : 80.5192 %
Group Cell : 19.4808 %
Bacterial Carpet: 50 m x 50 m
Chaotic Mixing with Bacterial Carpet
Baseline Dead Bacterial Carpet Live Bacterial Carpet
Depth: 15 mWidth: 200 m
0 5 10 15 20 250
2
4
6
8
10x 10- 7
D [
cm
2/s
]
Concentration of Bacteria [ x 108/ml]
BaselineDeadTumblyWild- type (1)Wild- type (2)Wild- type (3)
Baseline
Dead Bacterial Carpet
Live Bacterial Carpet
MJ Kim and KS Breuer, JFE, 2007
Active bacterial carpet in the microchannel (1 micron dia. fluorescence bead motion)
Autonomous Bacterial Pumping System
• Coat surface of racetrack with Serratia marcesens using flow-deposited carpet
• Seed with 500 nm fluorescent particles
• Pumping velocities ~ 10 m/sec in the racetrack microchannel
PD
F-10 -5 0 5 10 15 20 250
0.02
0.04
0.06
0.08
0.1
0.12
0.14
2 mm
200 m
50 m
1.6 mm
Channel Blockedby Glue (RTV)
Streamwise Drift Velocity [ m/s]
MJ Kim and KS Breuer, APS DFD Meeting. 2004
Fully Developed Pumping Velocity
Pumping Enhancements in the Open System:
1) Glucose (Food) Effects
2) Geometric Effects
Flagellar Motor Acitivities
Large-scale Self-coordinations
Various Effects on Bacterial Microfluidic Pumps
MJ Kim and KS Breuer, PNAS, In review. 2007
Autonomous Bacterial Transportation System
Micro-Barges:
- Fill Factor: 90 ~ 95 %
- Typical Velocity : ~ 5 m/s
- Chemotaxis, Phototaxis, and Aerotaxis
PDMS barge
Glass substrate
Microbarges in Motion
Engineered Bacterial Systems
Cell Patterning Using Colloidal Lithography
DK Yi, MJ Kim, et al. Biotech. Lett, 2006
Conclusions
ACKNOWLEDGEMENTS:
E. Steager (Ph.D), R. Mulero (Ph.D), C.-B Kim (PostDoc), C. Naik (UG), J. Patel (UG), L. Reber (UG), S. Bith (UG).
Kenny Breuer, Tom Powers (Brown), Howard Berg, Linda Turner (Harvard), Nick Darnton (U.Mass), MunJu Kim (U.Pittsburgh).