Yael Hanein - Micha E Spira

Carbon nanotube based multi
electrode arrays for neuronal
interfacing
Yael Hanein
School of Electrical Engineering
http://www.eng.tau.ac.il/~hanein
Mark Shein, Asaf Shoval, Nitzan Herzog, Moshe David-Pur,
Raya Sorkin, Alon Greenbaum, Tamir Gabay
Eshel Ben-Jacob
Amir Ayali, Sarit Anava
Evelyne Sernagor, Christopher Adams
Danny Baranes, Pablo Blinder
http://www.eng.tau.ac.il/~hanein
Cell-electrode Coupling
Electrolyte
Neuron
Soma
Rseal
Rspread
Re Ce
1
Rn ~
A
Csh
Rmet
Rmet
Chd
Csh
Re
Ce
Rspread
Chd
Rseal
Cell-substrate Interactions
Bio-Chemistry
Bio-Physics
Wong et al. Surface chemistry 2004
Nano-Topography and Cells
Si pillars
Craighead, Cornell
Carbon nanotubes
Mattson et al.
J. Mol. Neurosci 2000
Neuronal Circuits on a Chip
Mouse retina
Cell clusters
Single cells
A
80 µm
30 µm
CNTs and neurons
Outline
I. Carbon nanotubes (brief)
II. Carbon nanotube electrodes
III. Nanotube and neurons: Adhesion, patterning
IV. Neural circuits on CNT electrodes
V. Tension and neurons
VI. Process entanglement as anchorage mechanism
VII. CNT electrodes for retinal interfacing
I. Carbon Nanotubes
TEM
SEM
Carbon nanotubes
• Conducting and SC
• Extremely strong
• Extremely durable
• Inert
• Simple CVD process
Abrams, Lareah and Hanein, Nanotechnology 2007,
Abrams and Hanein JPC B 2006,
Abrams and Hanein, Carbon 2007
I. CNT Chemical Vapor
Deposition
• Nano-sized metal catalyst
• 900 deg process
• C2H4 or CH4
Z. R. Abrams, Y. Hanein et al. Nano Letters, 2007
II. CNT (carbon nanotube) MEA
SiO2
TiN
Si3N4
Si substrate
Ni+CNTs
Gabay et al. Nanotechnology, 2007
II. CNT (carbon nanotube) MEA
Gabay et al. Nanotechnology, 2007
II. Electrode Capacitance
Cyclic voltammetry
2D/3D Specific capacitance
CNTs
SiO2
TiN
Surface
Volume
CNTs
10 mF·cm−2
10 F·cm−3
CNT conductingpolymer composite
2.5 F·cm−2
TiN
10 mF·cm−2
II. AC Properties
Ze=R0 fm
Electrode
material
m
CNT
-0.1 - -0.4
PT Black
-0.6 - -0.8
II. Charge Injection Limit
2 µA pulse for 50 ms
Q=I×t=1×10-7 C
d = 80 µm
A = 5×10-5 cm2
Electrode
Material
QA
CNTs
2×10-3 C/cm2
Pt
5×10-4 C/cm2
AIROF
2×10-3 C/cm2
Activated iridium oxide
film
III. Network Engineering
Gabay et al. Physica A, 2005
Sorkin et al. J. Neural Engineering, 2006
IV. CNT Neuro Chip
Neurons (brain cells)
Electrodes
IV. Spontaneous Activity
Shein et al. Bio Med micro devices, 2009
IV. Circuits
Neuron and CNTs
• Why do (some) cells like rough
surfaces?
• What is the origin of the process
tautness?
• Why do cells cluster?
• Are all the above questions
related?
V. Role of Tension
• CNT islands function
as anchor sites (Do
CNT islands mimic
cells)
• Tension tightens
processes
• Tension introduces a
selection rule
Anava et al, Biophysical Journal 2009
VI. Cell-CNT Interaction
Gabay et al. Physica A, 2005
Sorkin et al. J. Neural Engineering, 2006
VI. Entanglement
Neurons
Glia
HRSEM
Fluorescence confocal
Sorkin et al., Nanotechnology 2009
VI. Twining
(c
)
(a
)
10µm
(b
)
(d
)
Binding Mechanism
Tendrils and processes
VII. Recording from Retina
• Mouse retinal whole mount
• Cone rod homebox knockout mouse
• RGC in direct contact with CNT electrodes
Target: 625 electrodes, center-center spacing = 20 µm
Evelyne Sernagor and Christopher Adams, UNC
VI. Retina on CNTs
A
B
*
100 µm
*
100 µm
Recordings
S/N=75
30 µm
CNT vs TiN
A
10 µV
TiN
5 ms
TiN
100 µV
20 ms
B
10 µV
CNT
5 ms
CNT
100 µV
20 ms
CNT vs TiN
A
120
Detected spikes
TiN MEA Electrode 42
TiN MEA Electrode 32
400
100
300
80
60
200
40
100
20
0
0
0
50
100
150
200
250
300
0
50
100
150
200
250
300
250
300
Amplitude (µV)
B
Detected spikes
140
140
CNT MEA MVP19b
Electrode 35
120
CNT MEA MVP19b
Electrode 47
120
100
100
80
80
60
60
40
40
20
20
0
0
0
50
100
150
200
250
300
0
50
Amplitude (µV)
100
150
200
CNT vs TiN
B
10
TiN MEA
Number of electrodes
Number of electrodes
A
8
6
4
2
0
-2
-1
0
1
2
6
CNT MEA
5
4
3
2
1
0
-2
-1
Amplitude growth rate (%/min)
0
1
2
Spike Amplitude
A
CNT MEA MVP13 - Electrode 75
Max
-100 µV
*
*
-200 µV
*
Mounting
B
+ 22 min
+ 28 min
+ 30 min
+ 47 min
0
Normalized
probability
CNT MEA MVP13 - Electrode 83
Max
-100 µV
-200 µV
Mounting
+ 22 min
+ 28 min
+ 30 min
+ 47 min
0
Normalized
probability
Summary
CNTs as a new bio-material
Strong cell-CNT binding
High quality recordings
Effective stimulation
Raya Sorkin
Moshe David-Pur
Alon Greenbaum
Mark Shein
Asaf Shoval
Stimulation
Charge injection limit:
30 µm
80 µm
80 µm electrodes, 480 µA
80 µm
A
*
10 ms
B
*
100 ms
T=60, 80, 100 µs
Specific Charge injection limit = 2×10-3 C/cm2 (un-modified)
80 mm electrodes: Charge injection limit = 100 nC
8-channel STG, by MC systems
III. Network Engineering (PDL)
Cells, axons and dendrites
red – axons, green –dendrites,
blue – cell body
Sorkin et al. J. Neural Engineering, 2006