WHY FUEL CELLS? Emission of toxic pollutants when fossil fuel burnsBuild-up of CO2 & other greenhouse gases leading to global warming Decline of world oil productionDeregulation of electricity supply industry
Advantages of Fuel Cells More efficient and convenient than internal combustion engines Modular Design •40-60% efficient Cogeneration •Zero-emission •Low maintenance costs Capacity to use different kinds of fuels •No moving parts More practical and cost effective than No moving parts batteries Fast response High specific energy and power High Efficiency Longer life (5-10 years vs. 1-3 for batteries) No emission of pollutants No long charging periods Lower capital cost in mass production No hazardous material disposal issues
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 2 mm 2 email@example.com
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 firstname.lastname@example.org
Figure 8.1. Schematic representations of nanocomposite materials with characteristic length scale: (a) nanolayered composites with nanoscale bilayer repeat length L; (b) nanofilamentary (nanowire) compositescomposed of a matrix with embedded filaments of nanoscale diameter d; (c) nanoparticulate composites composed of a matrix with embedded particles of nanoscale diameter d.
Ballistic Nanotube MOS Transistors (Chen,Hastings)Placement of Nanotubes by E-Field D Nanotube Field-Effect Transistor(FET) (The first-demo) Al-Gate SWNTL Drain Source d HfO2 W L Ti SiO2 L~20 nm E-Beam Lithography
Figure 20.1. Schematic illustrations of 1D, 2D, and 3D photoniccrystals patterned from two different types of dielectric materials.
Figure 20.3. (A) An illustration of the 3D woodpile lattice and (B) itsphotonic band structure calculated using the PWEM method. Thefilling fraction of the dielectric rods is 26.6%, and the contrast inrefractive index is set to be 3.6/1.0.(From Ref. 23 by permission ofElsevier 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.
Microarrays for Sensing Applications 50 mm Polymeric networks patterned onto silicon surfaces have potential application as recognition elements in biosensor applications.
Fig. 4 (a) A capacitive sensor structure and (b) Responseof the capacitive sensor using the vertically alignedMWNT’s in a template (Switch between 3% NH3 andpure N2).
Photonic Sensors: Self-Referencing Surface-Plasmon Resonance (SR-SPR) Sensing Self-referencing Surface-Plasmon • Surface-plasmon resonance: Resonance Sensor – 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?Students: R. Donipudi, P. Bathae Kumeresh; Funded by ORAU
MEMS Based Detection and Drug Delivery for Treatment of Coronary Heart Disease (Ehringer, Chien, Keynton, Walsh, Cohn, Hinds)Early detection of sudden heart dysfunction using a micro-fabricatedimplantable device to monitor vital cardiac chemical changesRapid recovery from an ischemic attack by providing an efficient ATPdelivery system to the heart.
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. Micro-/nanoscale biosensor Drug Delivery Microdevice
Fig 3 Nanoscale Electrode for in-vivo neurological recording.
Research Update III: Hippocampal Neuron Recordings in Awake Rats for up to 6 Months W4 ) . 8 1 ( 3 7 10 0 4 9 ( 1 2 . 1 ) 6 1 ( 1 5 . 1 ) mm Firing 20x150 µm Time → Spike Waveforms Firing Rate Stripcharts Place Fields (after 30 min) 1 month after implant 9 3 ( 2 3 . 1 ) 9 4 ( 2 3 . 2 )Site 3 Site 4 7 3 ( 1 8 . 1 ) 8 1 ( 2 0 . 1 ) Site 3 Firing Rate (Hz) 5 Site 4 150 µV DSP01b sig001 200 µs 12000 0 DSP03a 0 200 400 600 1 month sig003 Time (sec) 1 month 12000 8 2 ( 2 0 . 2 )Site 3 Site 4 6 months after implant Site 3 61(15.1) Firing Rate (Hz) 5 Site 4 150 µV 0 200 μs 0 200 400 600 ) 2 . 0 2 ( 2 8 Time (sec) 6 months 6 months Courtesy of Dr. Sam Deadwyler and Dr. Rob Hampson, Wake Forest Univ.
Research Update I: New Ceramic-Based Conformal Microelectrodes Serial W22.5 x 2.5 cm wafer 60 0 mmCeramic-based Microelectrodes Side-by-SideAl2O3 substrates 37.5 to 125 µm1. Polyimide coatings “Ceramic-based2. Pt or Ir recording sites Microarrays”3. “Multi-purpose” tip and long shank designs 20x150 µm
A group of near-naked protestors demonstratethe invasion of nanotechnology (into clothing)in front of the Eddie Bauer flagship store inChicago.The members of the group THONG (ToplessHumans Organized for Natural Genetics) wereupset the about the Nano-tex line of shirtsand khakis.(Popular Science, August 2005)
Andre Nel,1,2* Tian Xia,1 Lutz Ma¨dler,3 Ning Li1