Lecture 6. Nanotechnology Fuel Cells

Nano-composite materials

Nanoelectronics and photonic

Devices:

Chemical and Biological Detectors

Nanomedicine:

Disease Detection

Implants

Delivery of Therapeutics

Other nanomedicine

Applications

Risks

Fuel Cells

WHY FUEL CELLS?

Emission of toxic pollutants when fossil fuel burns

Build-up of CO2 & other greenhouse gases leading to global warming

Decline of world oil production

Deregulation of electricity supply industry

Advantages of Fuel Cells

Modular Design

Cogeneration

Capacity to use different kinds of fuels

No moving parts

Fast response

High Efficiency

No emission of pollutants

More efficient and convenient than internal

combustion engines

•40-60% efficient

•Zero-emission

•Low maintenance costs

•No moving parts

More practical and cost effective than

batteries

High specific energy and power

Longer life (5-10 years vs. 1-3 for

batteries)

No long charging periods

Lower capital cost in mass production

No hazardous material disposal issues

Polymer Electrolyte Membrane Fuel Cell (PEMFC)

http://www.celanesechemicals.us/index/about_index/innov-home/innov-fuelcell/fuel_cell_contacts/fuel_cell_pictures.htm

sjp@cie.unam.mx

sjp@cie.unam.mx

2 mm 2 mm

FUEL CELL MATERIALS

Fuel cells will power the new hydrogen economy; and advances in materials science, especially nanomaterials will be key to enabling this.

MEMBRANES

A critical challenge is finding effective membrane materials. Membranes which can function without pressure, temperature, hydration may reduce the cost and complexity

sjp@cie.unam.mx

FUEL CELL MATERIALS

Fuel cells will power the new hydrogen economy; and advances in materials science, especially nanomaterials will be key to enabling this.

ELECTRODES AND CATALYSTS

CO tolerant catalysts based on nanostructured Pt alloys are presently the most utilized. Critical challenges are finding new nanostructured catalytic materials and cheap synthesis routes.

Nanostructured Pt-Ru catalyst

• Composites

Figure 8.1. Schematic representations of nanocomposite materials with

characteristic length scale: (a) nanolayered composites with nanoscale

bilayer repeat length L; (b) nanofilamentary (nanowire) composites

composed of a matrix with embedded filaments of nanoscale diameter d;

(c) nanoparticulate composites composed of a matrix with embedded

particles of nanoscale diameter d.

• Nanoelectronics

Fig. 1 Scanning-electron micrograph of a Silicon-on-insulator integrated-

phontonic Device. [2,3]

Ballistic Nanotube MOS Transistors (Chen,Hastings)

Wd

D

L

SWNTSWNT

SiO2

Source

Al-Gate

Ti

HfO2

Drain

L

L~20 L~20 nmnm

Placement of Nanotubes by E-Field

(The first-demo) Nanotube Field-Effect Transistor(FET)

E-Beam Lithography

Other Applications

• Photonic Devices

Figure 20.1. Schematic illustrations of 1D, 2D, and 3D photonic

crystals patterned from two different types of dielectric materials.

Figure 20.3. (A) An illustration of the 3D woodpile lattice and (B) its

photonic band structure calculated using the PWEM method. The

filling fraction of the dielectric rods is 26.6%, and the contrast in

refractive index is set to be 3.6/1.0.(From Ref. 23 by permission of

Elsevier B.V.)

• • Figure 1 With the disordered lattice set up, the

researchers launched a weak probe beam and imaged the intensity distribution in the x–y plane downstream as the light passed through the material (see the figure). In transverse localization, a narrow beam propagating through a disordered medium undergoes diffusive broadening until its width becomes comparable to the localization length. The greater the disorder, the faster the beam evolves into the localized state.

• C. Chemical and Biological

Detectors

Polymeric networks patterned onto silicon surfaces have potential

application as recognition elements in biosensor applications.

50 mm

Microarrays for Sensing Applications

Fig. 4 (a) A capacitive sensor structure and (b) Response of the capacitive sensor using the vertically aligned MWNT’s in a template (Switch between 3% NH3 and pure N2).

• Surface-plasmon resonance: – widely used for chemical sensing and for

investigating bio-molecular interactions

– high sensitivity, label free approach that measures refractive index changes near a metal-solution interface

– most often measures binding of the target analyte to a functionalized surface, but

• How can one differentiate between specific binding, non-specific binding, and changes in solution refractive index?

• How can one integrate SPR on chip for multi-channel self-referenced sensing?

Photonic Sensors: Self-Referencing Surface-Plasmon Resonance (SR-SPR)

Sensing Self-referencing Surface-Plasmon

Resonance Sensor

Students: R. Donipudi, P. Bathae Kumeresh; Funded by ORAU

• Nanomedicine

A nanofilter from LabNow gives a fast count of white blood cells

Application as Functional Components of Novel Devices

• Nanomedicine

– Diagnosis • Imaging • Sensors • DNA Sequencing

– Arrays, Nanopore Sequencing

– Therapeutics • Surgery • Drug Development

– Arrays, Local Cellular Delivery

• Drug Delivery – Microchip, Microneedles, Micro-/Nano-sphere

• Tissue Engineering

1.Disease detection

Fig 3 Nanoscale Electrode for in-vivo neurological recording.

Fabrication process is summarized. (a) Free-standing membranes are spin coated with positive e-beam resist, and e-beam lithography is performed. (b) The nanohole pattern is transferred to SiNx membrane through RIE processes. (c) Oxygen cleaning process results in a free-standing photonic crystal-like structure. (d) Metal deposition results in a free-standing optofluidic nanoplasmonic biosensor with no clogging of the holes. (e) Scanning electron microscope images of patterned SiNx membrane is shown before gold deposition. (f) Gold deposition result in suspended plasmonic nanohole sensors without any lift-off process. No clogging of the nanohole openings is observed (inset).

Published in: Ahmet A. Yanik; Min Huang; Osami Kamohara; Alp Artar; Thomas W. Geisbert; John H. Connor; Hatice Altug; Nano Lett. 2010, 10, 4962-4969. DOI: 10.1021/nl103025u Copyright © 2010 American Chemical Society

(a) Immunosensor surface functionalization is illustrated in the schematics. Antiviral immunoglobulins are attached from their Fc region to the surface through a protein A/G layer. (b) Sequential functionalization of the bare sensing surface is illustrated (black) for the optofluidic nanohole sensors with a sensitivity of FOM ∼ 40. Immobilization of the protein A/G (blue) and viral antibody monolayer (red) result in the red shifting of the EPT resonance by 4 and 14 nm, respectively.

Published in: Ahmet A. Yanik; Min Huang; Osami Kamohara; Alp Artar; Thomas W. Geisbert; John H. Connor; Hatice Altug; Nano Lett. 2010, 10, 4962-4969. DOI: 10.1021/nl103025u Copyright © 2010 American Chemical Society

Detection of PT-Ebola virus (a) and Vaccinia (c) viruses shown in spectral measurements at a concentration of 108 PFU/mL. (c, d) Repeatability of the measurements is demonstrated with measurements obtained from multiple sensors (blue). Minimal shifting due to nonspecific bindings is observed in reference spots (red). Here, the detection sensors are functionalized with M-DA01-A5 and A33L antibodies for capturing PT-Ebola and Vaccinia viruses, respectively.

Published in: Ahmet A. Yanik; Min Huang; Osami Kamohara; Alp Artar; Thomas W. Geisbert; John H. Connor; Hatice Altug; Nano Lett. 2010, 10, 4962-4969. DOI: 10.1021/nl103025u Copyright © 2010 American Chemical Society

2.Implants

3.Delivery of Therapeutics

(Ehringer, Chien, Keynton, Walsh, Cohn, Hinds)

MEMS Based Detection and Drug Delivery for Treatment of Coronary Heart Disease

Early detection of sudden heart dysfunction using a micro-fabricated implantable device to monitor vital cardiac chemical changes

Rapid recovery from an ischemic attack by providing an efficient ATP delivery system to the heart.

Drug Delivery into Neural Tissue (Cornell)

Self-regulated Drug Delivery Devices • Micro- and nanofabricated devices have many potential applications in medicine

• For example, drug delivery devices can be combined with biosensors to create micro- and nanoscale self-regulated drug delivery devices

MicroCHIPS, Inc.

Drug Delivery Microdevice Micro-/nanoscale biosensor

• Other Nanomedicine Applications

Fig 3 Nanoscale Electrode for in-vivo neurological recording.

Research Update III: Hippocampal Neuron Recordings in Awake Rats for up to 6

Months

Place Fields (after 30 min)

W4

20x150 µm

100 mm

61(15.1)

73(18.1)73(18.1)73(18.1)

Time →

Firing

Spike Waveforms Firing Rate Stripcharts

DSP03asig00312000

DSP01bsig00112000

Site 3 Site 4

6 months after implant

150 µV

200 µs

150 µV

200 μs

Site 3 Site 4

73(18.1)82(20.2)

4 9 ( 1 2 . 1 ) 6 1 ( 1 5 . 1 )

9 3 ( 2 3 . 1 ) 9 4 ( 2 3 . 2 )

7 3 ( 1 8 . 1 ) 8 1 ( 2 0 . 1 )

8 2 ( 2 0 . 2 )

Site 3

0 200 400 600 Time (sec)

0

5

Site 4

Firi

ng

Rat

e (H

z)

Site 3

0 200 400 600 Time (sec)

0

5 Site 4

Firi

ng

Rat

e (H

z)

1 month after implant

Courtesy of Dr. Sam Deadwyler and Dr. Rob Hampson, Wake Forest Univ.

1 month

6 months

1 month

6 months

“Ceramic-based

Microarrays”

2.5 x 2.5 cm wafer

Side-by-Side

Serial

Research Update I: New Ceramic-Based Conformal Microelectrodes

Ceramic-based Microelectrodes

Al2O3 substrates 37.5 to 125 µm

1. Polyimide coatings

2. Pt or Ir recording sites

3. “Multi-purpose” tip and long shank designs

W2

20x150 µm

600 mm

CA1

CA3

DG

1 2

4 3

Ceramic Probe

MRI of Macaque Brain

W4

20x150 mm

Co

un

ts/b

in

0 20 40 60 80 0

0.5 1

1.5 2

0 20 40 60 80 0

0.5 1

1.5 2 Site 1

0 20 40 60 80 0

0.5 1

1.5 2 Site 2

0 20 40 60 80 0

0.5 1

1.5 2 Site 3

Site 4

Hippocampus

Research Update IV:

Electrophysiological

Recordings in

Nonhuman Primates

150 µV

200 µs

1

2

4

3

Recording Sites

Time (ms)

-10 -5 0 5 10

Firin

g R

ate

(H

z)

0

2

4

6

8

10

Time (ms)

-10 -5 0 5 10

0

2

4

6

8

10

Time (ms)

-10 -5 0 5 10

0

2

4

6

8

10

Time (ms)

-10 -5 0 5 10

0

2

4

6

8

10

Site 1

Site 2

Site 2a

Site 3

Site 3a

Site 4

Stim: 100 µA 250 μA 500 µA 1 mA W2

20x150 µm

600 mm

Record CA1

Stimulate CA3

Research Update II: Simultaneous Stimulation and Recordings

1

3

2

4

CA1

CA3

S S

Recording Sites

S = Stimulation Sites

150 µV

200 µs

From: Patricia J. Cooper, Ming Lei, Long-Xian Cheng, and Peter Kohl J Appl Physiol 89: 2099-2104, 2000

10 mm

Diameter: 12 mm Compliance: 80 mm/mN, 4 mm/mN

Institute of Molecular Medicine

NanoMedicine Project 3

Objective: To use hollow nanotubes as a delivery vehicle for

small interference RNA (RNAi) to silence specific gene products.

Institute of Molecular Medicine

RNA injection via nanotubes

Institute of Molecular Medicine

Force Transducer Step Motor

Carbon Fiber for manipulating single cell

Institute of Molecular Medicine

• Other Nanomedicine Opportunities

• RISKS

A group of near-naked protestors demonstrate the invasion of nanotechnology (into clothing) in front of the Eddie Bauer flagship store in Chicago. The members of the group THONG (Topless Humans Organized for Natural Genetics) were upset the about the Nano-tex line of shirts and khakis. (Popular Science, August 2005)

Andre Nel,1,2* Tian Xia,1 Lutz Ma¨dler,3 Ning Li1