Building Neural Networks on Carbon Nanotube Substrates

Weijian Yang

Department of Electrical Engineering and Computer SciencesUniversity of California, Berkeley, CA, 94720, USA

UC Berkeley 2EE 235 Presentation 2 Weijian Yang May 4, 2009

From Neuron to Neural Networks How do the neurons connect with each other to

form a network?

http://www.nih.gov/news/research_matters/july2006/07142006gene.htm

http://www.joejoe.org/forum/index.php?showtopic=7945

Ref. 1, 2

3 um150 um

UC Berkeley 3EE 235 Presentation 2 Weijian Yang May 4, 2009

Outline 1. Nano carbontubes boost neuronal electrical signaling Viviane Lovat, et.al. Nano Lett., 5, 1107, 2005.

2. Engineering the neural network with patterned nano carbontubes substrates.

Tamir Gabay, et.al. Physica A, 350, 611, 2005.

3. Outreach Understanding the brain, from neuron to mind. Harvard

Magazine, edited by Courtney Humphries, May 2009.

UC Berkeley 4EE 235 Presentation 2 Weijian Yang May 4, 2009

Carbon Nanotubes as Substrates Why carbon nanotubes? Surface texture at the scale of ~10 to ~100 nm,

aspect ratio similar to the nerve fiber. High electrical conductivity. Strong mechanical strength. Chemical functionalization.

Good biocompatibility!

Ref. 1-4

UC Berkeley 5EE 235 Presentation 2 Weijian Yang May 4, 2009

Boost Neuronal Electrical Signal Hippocampal neuron growing on dispersed

MWCNT in culture medium.

Ref. 1

UC Berkeley 6EE 235 Presentation 2 Weijian Yang May 4, 2009

Boost Neuronal Electrical Signal

Improve neural signal transfer. Increase network activity. Reinforce electrical coupling between neurons.

Spontaneous postsynaptic current Membrane potential

Ref. 1

UC Berkeley 7EE 235 Presentation 2 Weijian Yang May 4, 2009

Pattern the Neuron Network

catalyst

150 um

MWCNT

Ref. 2

UC Berkeley 8EE 235 Presentation 2 Weijian Yang May 4, 2009

Network Evolution

One hour after cell deposition

After 96 hours

Neurons’ surface mobility and selective adhesion are the driving mechanism for the well organized placement at the CNT sites.

Ref. 2

100 um150 um

UC Berkeley 9EE 235 Presentation 2 Weijian Yang May 4, 2009

Network Evolution

96 hours

128 hours

150 hours

A single link is formed between the two nearest neighbors.

Connection is reinforced with respect to time.

A bundle is eventually formed to establish a tensed link between two islands. Ref. 2

150 um

UC Berkeley 10EE 235 Presentation 2 Weijian Yang May 4, 2009

Summary Carbon nanotubes are highly biocompatible for

neural network. (surface morphology, electrical, mechanical and chemical properties.)

Well defined engineered cultured neural systems can be formed on high density carbon nanotube islands.

A powerful platform to study neuronal adhesion, neurite outgrowth, and the neural network.

UC Berkeley 11EE 235 Presentation 2 Weijian Yang May 4, 2009

Outreach Nanowire is also a good candidate for the research into

neural network. (especially in electrical, chemical, and biological signal detection.)

Ref. 5, 6

UC Berkeley 12EE 235 Presentation 2 Weijian Yang May 4, 2009

Reference1. Viviane Lovat, et.al, “Nano Carbontubes Boost Neuronal Electrical Signaling,” Nano

Lett., 5, 1107, 2005.

2. Tamir Gabay, et.al, “Engineering the Neural Network with Patterned Nano Carbontubes Substrates,” Physica A, 350, 611, 2005.

3. Miguel A. Correa-Duarte, et. al, “Fabrication and Biocompatibility of Carbon Nanotube-Based 3D Networks as Scaffolds for Cell Seeding and Growth,” Nano Lett., 4, 2233, 2004.

4. Hui Hu, et. al., “Chemically Functionalized Carbon Nanotubes as Substrates for Neuronal Growth,” Nano Lett., 4, 507, 2004.

5. Fernando Patolsky, et. al. “Detection, Stimulation, and Inhibition of Neuronal Signals with High-Density Nanowire Transistor Arrays,” Science, 313, 1100, 2006.

6. “Understanding the brain, from neuron to mind,” Harvard Magazine, edited by Courtney Humphries, May 2009.

UC Berkeley 13EE 235 Presentation 2 Weijian Yang May 4, 2009

Thank you!

Thank you!