Presentation on theme: "Carbon Nanotube Applications"— Presentation transcript:
1Carbon Nanotube Applications J.-C. CharlierNorma RangelNanotechnology3/2/2010Scott DoughertyUniversity of Texas at Dallas
2Outline Introduction Application of Carbon Nanotubes PropertiesFabrication processesApplication of Carbon NanotubesElectronicUnzipping of CNTsStructural and Mechanical: CompositesSensors, NEMS, Bio: MicroscopyBiosensors: DNA sequencingPaper: Promises, facts and challenges for CNTs in imaging and therapeuticsFuture Work, conclusions
3Carbon nanotubes CNT is a tubular form of carbon CNT is a tubular form of carbonLength: few nm to microns.CNT is configurationally equivalent to a two dimensional graphene sheet rolled into a tube.Can be functionalized
4Outline Introduction Application of Carbon Nanotubes PropertiesFabrication processesApplication of Carbon NanotubesElectronicUnzipping of CNTsStructural and Mechanical: CompositesSensors, NEMS, Bio: MicroscopyBiosensors: DNA sequencingPaper: Promises, facts and challenges for CNTs in imaging and therapeuticsFuture Work, conclusions
5Electrical properties Electrical conductivity six orders of magnitude higher than copper‘tunable’ bandgap: electronic properties can be tailored through application of external magnetic field, application of mechanical deformation…Very high current carrying capacityExcellent field emitterHow nanotechnology worksCNT can be metallic (armchair) or semiconducting, depending on chirality.
6Mechanical Properties The strongest and most flexible molecular material because of C-C covalent bonding and seamless hexagonal network architectureYoung’s modulus of over 1 TPa vs 70 GPa for Aluminum, 700 GPA for C-fiberMaximum strain ~10% much higher than any materialThermal conductivity ~ 3000 W/mK in the axial direction with small values in the radial directionWikipedia
7Outline Introduction Application of Carbon Nanotubes PropertiesFabrication processesApplication of Carbon NanotubesElectronicUnzipping of CNTsStructural and Mechanical: CompositesSensors, NEMS, Bio: MicroscopyBiosensors: DNA sequencingPaper: Promises, facts and challenges for CNTs in imaging and therapeuticsFuture Work, conclusions
9SWCNTs on Patterned Surfaces Surface masked by a 400 mesh TEM gridMethane, 900° C, 10 nm Al/1.0 nm Fe/0.2 nm Mo
10Surface masked by a 400 mesh TEM grid; 20 nm Al/ 10 nm Fe; nanotubes grown for 10 minutes (a) “Farms” of carbon nanotubes and (b) a closeup of one farm. Livermore is exploring the potential of such nanotube arrays for detection applications.Grown using ethylene at 750o CChristine Orme
11Outline Introduction Application of Carbon Nanotubes PropertiesFabrication processesApplication of Carbon NanotubesElectronicUnzipping of CNTs and fibersStructural and Mechanical: CompositesSensors, NEMS, Bio: MicroscopyBiosensors: DNA sequencingPaper: Promises, facts and challenges for CNTs in imaging and therapeuticsFuture Work, conclusions
12CNT Applications: Electronics CNT quantum wire interconnectsField emitters for instrumentationDiodes and transistors for computingFlat panel displaysCapacitorsTHz oscillatorsData Storage• Control of diameter, chirality• Doping, contacts• Novel architectures (not CMOS based!)• Development of inexpensive manufacturing processesChallengesAMES Research center, NASA
13Mechanism of carbon-nanotubes unzipping into graphene ribbons (a-f) Gradual unzipping of a (5,5) CNT. Pairs of oxygen atoms are added sequentially. The edges of the unopened (5,5) CNT are passivated with hydrogen atoms and the optimized structure (right) opens only on the internal edge.D. V. Kosynkin, et. al., Nature London 458,Rangel et. al., JCP 2009
14CNT Applications: Structural and Mechanical High strength compositesHeat exchangers, radiators, thermal barriers, cryotanksCables, tethers, beamsRadiation shieldingMultifunctional materialsFilter membranes, supportsFunctionalize and use as polymer back bone- plastics with enhanced properties like “blow molded steel”Body armor, space suits- Control of properties, characterization- Dispersion of CNT homogeneously in host materials- Large scale production- Application developmentChallengesAMES Research center, NASA
15Production of sheets of carbon nanotube “textile” Production up to 7 meters per minuteTransparent and stronger than a sheet of steelCSIRO and the University of Texas at Dallas
16Dispersal of CNTs in Metal Matrix “One of the major obstacles to the effective use of carbon nanotubes as reinforcements in metal matrix composites is their agglomeration and poor distribution/dispersion in the metallic matrix.” – Morsi & Esawi, 2007Ball MillingMost popular by farVarious times/ratesPestle and MortarMore Complex Processes“Molecular Level Process”Crucible-based processDpowd = 70 μm (approx)DCNT = 40 nm (approx)Human hair (D~50 μm)9cm
17Ag Cu Hardness Resistivity [Feng et al, Mater. Cha. Eng, 2005]Resistivity[Deng et al, Mater. Sci. Eng, 2007][Feng et al, Mater. Cha. Eng, 2005][Feng et al, Mater. Cha. Eng, 2005]Agglomeration of CNTs in a re-pressed composite containing 12% vol. CNT
18CNT Applications: Sensors, Microscopy CNT based microscopy:Nanoscale reactors, ion channelsNanotube sensors: force, pressure, chemical, BiosensorsBiomedicalin vivo real time crew health monitoringLab on a chipMolecular gears, motors, actuatorsDrug deliveryDNA sequencingArtificial muscles, bone replacement,Batteries, Fuel Cells: H2, Li storagebionic eye, ear, human organs• Controlled growth• Functionalization withprobe molecules, robustness• Integration, signal processing• Fabrication techniquesChallenges
19CNT Applications: Microscopy Conventional silicon or tungsten tips wear out quickly.CNT tip is robust, offers amazing resolution.Small diameter – maximum resolutionExcellent chemical and mechanical robustnessHigh aspect ratio
20CNT as Functional AFM tips Molecular-recognition AFM probe tips:Certain bimolecular is attached to the CNT tipThis tip is used to study the chemical forces between molecules – Chemical force microscopyInstitute of Optics, University of Rochester
21CNT Applications: Biosensors sensors for cancer diagnosticsIdentified probe molecule that will serve as signature of leukemia cells, to be attached to CNTMechanism: Current flow due to hybridization will be through CNT electrode to an IC chip.Prototype biosensors catheter development• High specificity• Direct, fast response• High sensitivity• Single molecule and cell signal capture and detectionChallenges
22CNT Biological applications: DNA sequencing Nanotube fits into the major grove of the DNA strandApply bias voltage across CNT, different DNA base-pairs give rise to different current signalsWith multiple CNT, it is possible to do parallel fast DNA sequencingTop view and side view of theassembled CNT-DNA systemInstitute of Optics, University of Rochester
23Outline Introduction Application of Carbon Nanotubes PropertiesFabrication processesApplication of Carbon NanotubesElectronicUnzipping of CNTsStructural and Mechanical: CompositesSensors, NEMS, Bio: MicroscopyBiosensors: DNA sequencingPaper: Promises, facts and challenges for CNTs in imaging and therapeuticsFuture Work, conclusions
24Promises, facts and challenges for carbon nanotubes in imaging and therapeutics K. Kostarelos, A. bianco and M. Prato Nature nanotechnology | VOL 4 | OCTOBER 2009 |Why CNTs?They can be easily internalized by cells and therefore can act as delivery vehicles for a variety of molecules relevant to therapy and diagnosis.As produced CNTs are insoluble in most organic or aqueous solvents, therefore for biological applications the surface should be modified.Toxicity effects are under debate
25Advantages of CNTs over nanoparticles: the degree of aggregation and the individualization of nanotube materials in the biological milieu (blood, intraperitoneal, interstitial fluids, and so on) have an important role in their pharmacological performance.Physical properties of CNTs allow efficient electromagnetic stimulation and detection.Advantages of CNTs over nanoparticles:Larger inner volumes – can be filled with chemical or biological species.Open mouths of nanotubes make the inner surface accessible and can be modified.
26Types of carbon nanotube studied in vivo for imaging and therapy. All in vivo studies using CNT so far have used one of these types:Pristine CNTsCoated CNTs (non-covalent surface modifcation)a, Pristine carbon nanotubes (CNTs) are those without any surfacemodification. b, Lipid‑coated nanotubes (primarily single‑walled nanotubes) with or without PEGylated lipids and other versions of further modified lipidmolecules. c, Copolymer or surfactant‑coated nanotubes (primarily single‑walled nanotubes). PEO is polyethylene oxide; PPO is polypropylene oxide.d, Single‑stranded DNA (ssDNA)‑coated nanotubes (primarily single‑walled nanotubes). e,f, Chemically functionalized nanotubes (both single‑walled andmultiwalled nanotubes) by 1,3 dipolar cycloaddition (e) and by acid oxidation (f).Functionalized CNTs (covalent surface modifcation)
27Preclinical in vivo studies using carbon nanotubes The majority of preclinical models have focused on oncology
29CNTs toxicity in biomedicine Focused in pristine CNTs, administrated by pulmonary routes.Material, doses and administration are not relevant to medical applications.Evidence of prolonged accumulation of long, rigid pristine CNTS associated with Cancer risks.
30Toxicity studies of CNTs developed for medical imaging and therapy
32CNTs in Medicine Q&A Are carbon nanotubes really useful in medicine? Proof-of-principle studies indicate that carbon nanotubes may help treat various diseases (cancer, AIDS, malaria, metabolic diseases), but only one study so far has reported a therapeutic outcome (prolonged survival) in a preclinical human-tumour model.Challenges:Nanotubes may not treat disease more effectively than established technologies.The risk-to-benefit ratio offered by nanotube-based therapeutics and diagnostics may weigh towards the risk.Opportunities:The possible contributions of nanotubes in medicine are almost unlimited and wide-ranging, from advanced delivery systems, electrodes and biosensors to probes for diagnostics and treatment- monitoring devices.Can carbon nanotubes help cure cancer?It is too early to determine because only early-stage preclinical studies are available and at present there are no clinical studies underway.
33CNTs in Medicine Q&ACan carbon nanotubes act as ‘nanorobots’ in the blood stream?A: Injectable nanorobots have not yet been developed, and active navigation of nanoparticles in the blood stream has not been achieved. Therefore, nanotubes can neither act as nanorobots nor be navigated in the blood stream.Challenges:Nanotubes as components of nanorobots and other nanomachines that may accumulate and intoxicate the body.Opportunities:Carbon nanotubes can act as components of nanofabricated machinery and offer tremendous capabilities — for example in wireless communication and monitoring between the patient and the clinician.
34CNTs in Medicine Q&AAre carbon nanotubes biocompatible and what does that mean?The term ‘biocompatibility’ implies the ability to interact with the biological milieu without adverse reactions.Chemically functionalized nanotubes have been shown by many groups to be more biocompatible (no immune or acute inflammatory responses) than pristine nanotubes.Challenges:Some types of carbon nanotubes or their impurities may accumulate in the body, leading to deposits that may cause unwanted side effects in the long-term.Opportunities:New carbon nanotube materials and strategies to make them biocompatible are actively pursued.
35CNTs for imaging and therapy Q&A Are carbon nanotubes toxic?Toxicity depends strongly on the type of nanotube, the dose, the route of administration and the tissue that is most affected.Pristine nanotubes have been shown to activate various mechanisms associated with toxicity, however these effects are shown to be remarkably reduced when properly functionalized with chemical groups.So far, no in vivo study using the types of nanotubes developed for medical purposes has reported adverse effects.Challenges:The structural similarity and association between carbon nanotubes and the carcinogenic asbestos fibresOpportunities:Systematic toxicological studies of carbon nanotubes to make them the ‘standard’ fibrilar nanomaterial.Need to determine the extent of toxicological risks from using nanotubes, their doses, types and route of administration.
37Future Work Already in product: CNT tipped AFM Big hit: CNT field effect transistors based nano electronics.Futuristic: CNT based OLED, artificial musclesComparison with well stablished alternativesChallengesImprove dispersion of carbon nanotubes in matricesImprove bonding to matrixManufacture: Important parameters are hard to control.Large quantity fabrication process still missing.Manipulation of nanotubes.
39G5 Rebuttal: Carbon-Nanotubes Applicattions Norma L. Rangel
40Norma Rangel – Rebuttal The overall presentation was good. However, from my point of view, it would have been better if instead of presenting that large variety of applications, the presentation have focused on maybe one or two and discuss more about the experimental details such as functionalization process the change in properties after functionalization and the physics behind each process.I understand this concern, however, the topic was “CNTs” which made it to wide and broad, therefore I tried to present as much as information as I could.Nevertheless no application was analyzed carefully enough, I mean the methodology and results were not analyzed in detail. The basic working principle used in the applications was not illustrated.The purpose of my presentation was to give an overview to the audience (mostly undergraduate students) some insights about CNTs basics and applications, which included a fair amount of information from several papers. I understande the reviewer’s concern but I think this could be solve if the audience were more uniform, that is, with the same background and level, also more technical lectures about for example specific fabrication process.The challenges shown in the last slide were general problems currently faced to make CNTs applications commercially available. The presenter didn’t make any suggestion on how to solve those problems.Right, my personal opinion about CNTs was not shown in the presentation, I would rather use other materials such as graphene to replace CNTs.
41On the nanotube textile slide, how are nanotubes separated into the rope of nanotubes? More details on the initial process to grabbing the first few threads of NWs may help.This is an interesting question, but unfortunately I don’t know the answer and I check my references and is not mentioned anywhere, we would need to contact the authors in order to get this information.Is the “preclinical human-tumor model” on the slide 32 a computer model simulation or a biological experimental model?Experimental, a tumor is grown in a laboratory.What makes CNTs good candidate over other materials/structures for a biomedical device?Due to the nanometer size of the nanotube -> can be introduce in the cells.Tube shape -> useful to place the treatment inside and drug delivery.Properties -> Strength, stability under harsh conditions. Spectroscopy and fluorescence detection.Are there any other structures or materials that can also be used for the applications discussed in the presentation?Nano-particles have shown good performance for cancer treatment and have been already applied in current biomedical technologies.
42Review of Carbon-Nanotubes Applicattions by Edson Bellido G1Review of Carbon-Nanotubes Applicattionsby Edson Bellido
43The presenter explained the synthesis methods currently being used, the most important properties of carbon nanotubes and a vary large variety of applications, focusing principally on the used of CNTs for imaging and therapeutics. She point out the challenges and opportunities of using CNTs in vivo.The presenter discuss about the importance of the functionalization of CNT to be able to use it in medicine applications since the CNTs by itself are not soluble on water and form bundles that could be toxic and can accumulate in the organs.The overall presentation was good. However, from my point of view, it would have been better if instead of presenting that large variety of applications, the presentation have focused on maybe one or two and discuss more about the experimental details such as functionalization process the change in properties after functionalization and the physics behind each process.
44Review of CNTs applications lecture It was summarized very well the physical properties of CNTs whichmakes it an outstanding material.A very broad range of applications for carbon nanotubes was shown.Nevertheless no application was analyzed carefully enough,I mean the methodology and results were not analyzed in detail.The basic working principle used in the applications was not illustrated.The challenges shown in the last slide were general problems currentlyfaced to make CNTs applications commercially available. The presenterdidn’t make any suggestion on how to solve those problems.Alfredo D. Bobadilla
45Review: Carbon Nanotube Applications By Mary Coan
46Review Overall a GREAT presentation Carbon Nanotubes have many properties that can not be found in any other materialHave many applictions:Diodes, Capacitors, Flat panel displays, etc…Challenges were discussedControl of diameterManufacturing costsExplained many different applications, processes, mechanisms and challengesReview
47Review Discussed typical questions regarding CNTs Example: CNTs in Medicine (Good?)Discussed the opportunities and challenges for each question discussedThe toxicity of CNTs was discussedShe did a wonderful job by using many images to describe what she was discussing.The level of the work presented fits the audience very well.Review
48Review Carbon Nanotubes (G5) Diego A. Gomez-Gualdron
49CNT properties Outstanding electrical conductivity (six times copper) Outstanding mechanical properties (tensile strength, yet flexible)Field emitters (they can increase resolution in spectroscopy)One-dimensional thermal conductivityEasy functionalizationEnhanced mass transport through the nanotube
50Production methods Large scale Small scale Chemical Vapor Deposition CVD schematicsPrecursor gasSubstrateNanotubecatalystSmall scaleLaser AblationArc dischargeModified from ASIN group
51Applications Microchips elements of reduced size Composite materials for extreme conditionsNanosensors for chemical and medical applicationsDrug delivery and cancer treatment
52AssessmentElectronic applications depending on selective production of pure semiconductor/conductor nanotubes at large scaleBiomedical applications still have to solve citotoxicity issues and treatment effectivenessMechanical applications pending on nanotube cost issues
53ReviewA good presentation overall. A wide range of applications were shown. Good assessment of status and challenges for each application. Good fluency despite the recurrence of filler words and mumbling during slide transitions. The speaker was confident during the presentation, although not so much during questions. The figures/text balance on the slides could improveIt would have been nice to stress what particular property of the nanotube is being taken advantage of for each specific application (why is the nanotube used for that specific application and not another material)
55QuestionsOn the nanotube textile slide, how are nanotubes separated into the rope of nanotubes? More details on the initial process to grabbing the first few threads of NWs may help.Is the “preclinical human-tumor model” on the slide 32 a computer model simulation or a biological experimental model?What makes CNTs good candidate over other materials/structures for a biomedical device?Are there any other structures or materials that can also be used for the applications discussed in the presentation?Jung Hwan Woo