Presentation on theme: "Mechanical and Industrial Engineering University of Massachusetts Amherst, MA, USA Nano-Impact Jonathan P. Rothstein 1 and Mark Tuominen 2 1. Mechanical."— Presentation transcript:
Mechanical and Industrial Engineering University of Massachusetts Amherst, MA, USA Nano-Impact Jonathan P. Rothstein 1 and Mark Tuominen 2 1. Mechanical and Industrial Engineering Dept. 2. Physics Dept. University of Massachusetts Amherst
Making a Better Bulletproof Vest A group of researchers at Univ. Del. have impregnated Kevlar vests with a nanoparticle colloidal suspension resulting in a dramatic improvement in projectile impact. The addition of a very small amount of fluid increased performance equivalent to doubling the number of Kevlar sheets while not changing flexibility of fabric. Why? Lee, Wetzel and Wagner J. Material Science (2003) Kevlar Kevlar & Nanoparticle Suspension
Making a Better Bulletproof Vest A group of researchers at Univ. Del. have impregnated Kevlar vests with a nanoparticle colloidal suspension resulting in a dramatic improvement in projectile impact. The addition of a very small amount of fluid increased performance equivalent to doubling the number of Kevlar sheets while not changing flexibility of fabric. Why? Kevlar Kevlar & Nanoparticle Suspension
Nanoparticle Suspensions The nanoparticle (d = 13nm) suspensions are shear thickening – the faster you shear or stretch them more viscous (thick) they become. The dramatic increase in viscosity dissipates energy as the Kevlar fibers are pulled out by the impact of the bullets. Increasing Stretch Rate
Why Size Matters For large particles the fluid remains Newtonian like air or water below 30wt% Above 30% interactions between and collisions of particles result shear thickening and elastic effects – particles interact to form large aggregate structures For nanoparticles, the effect of nanoparticle addition can be observed at concentrations closer to 1wt% - why? Surface area increases with reduced particle size resulting in enhanced interparticle interactions At same volume fraction smaller particles are packed closer together – electrostatic interactions are stronger and diffusion is faster so they interact more frequently. 1 m Particles 100nm Particles 10nm Particles
Copying Nature – Biomimetic Superhydrophobic Surfaces The leaves of the lotus plant are superhydrophobic – water beads up on the surface of the plant and moves freely with almost no resistance making the leaves self-cleaning. The surface of the lotus leaf has 10 m sized bumps which are coated by 1nm sized waxy crystals which make the surface extremely hydrophobic - repel water. The water does not wet the entire surface of the leaf, but only the tops of the large scale roughness. Synthetic superhydrophobic surfaces have designed to produce stain-resistant clothing and coatings for buildings and windows to make them self-cleaning. Water Drops on a Lotus Leaf
Drop Motion on a Superhydrophobic Surfaces Droplets dont wet, but roll down superhydrophobic surfaces. Water-based stains dont adsorb. Dirt is picked up by rolling drop as it moves – self cleaning surfaces Superhydrophobic Surface Dirt
Make Your Own Superhydrophobic Surfaces Need: two identical pieces of Teflon, sandpaper (240 grit) and a pipette full of water. Keep one piece of Teflon smooth. Lightly sand the second piece of Teflon with a random motion of the sandpaper to impart micron and nanometer size surface roughness. Smooth Teflon Sanded Teflon Experiment: Place a small drop of water on the smooth Teflon surface. Tilt the surface through vertical. Does the drop stick or slide? Now place a small drop on the sanded Teflon surface Tilt the surface through vertical. Can you get the drop to stick? Adding micron and nanometer surface roughness can have a big impact on how drops adhere to and wet a surface
Using Superhydrophobic Surfaces to Reduce Drag We are currently using superhydrophobic surfaces to develop a passive, inexpensive technique that can generate drag reduction in both laminar and turbulent flows. This technology could have a significant impact on applications from microfluidics and nanofluidics to submarines and surface ships. How does it work? The water touches only the tops of the post and a shear-free air-water interfaces is supported – effectively reducing the surface area. Currently capable of reducing drag by over 70% in both laminar and turbulent flows! w d 15μm On PDMS Hierarchical Nanostructures On Silicon
Can These Surfaces Have a Real Impact? 60μm Current Energy Resources – Fossil Fuels Increasing scarcity Increasing cost Dangerous to maintain security Ocean-going vessels accounted for 72% of all U.S. imports in 2006 Technology could be employed to make ships more efficient or faster Friction drag accounts for 90% of total drag experienced by a slow moving vessel A 25% reduction in friction drag on a typical Suezmax Crude Carrier could… Save $5,500 USD / day in #6 fuel oil Prevent 43 metric tons of CO 2 from entering the atmosphere each day The GENMAR GEORGE T (Japan Universal Shipbuilding, Tsu shipyard)
Why Size Matters To support larger and larger pressures and pressure drops, the spacing of the roughness on the ultrahydrophobic surfaces must be reduced into the nanoscale. Currently developing processing techniques for large area nanofabrication of superhydrophobic surfaces with precise patterns of surface roughness. Roll-to-roll nano-imprint lithography – a cutting edge tool. Supply Drive Module Coating Module Imprinting Module Receive Drive Module
Why Roll-to-Roll Nanoimprint Lithography Roll-to-roll technology will enable fabrication of nanostructured materials and devices by a simple, rapid, high volume, cost-effective platform. Current cost of nanofabrication is $25,000/m 2 This technology capable of pushing it to $25/m 2 Will help address many of the challenges facing society. Supply Drive Module Coating Module Membranes and Filters
Some key challenges facing society Water Energy Health Sustainable development Environment Knowledge Economy
Global Grand Challenges 2008 NAE Grand Challenges
Top Program Areas of the National Nanotechnology Initiative for Fundamental nanoscale phenomena and processes 2. Nanomaterials 3. Nanoscale devices and systems 4. Instrumentation research, metrology, and standards 5. Nanomanufacturing 6. Major research facilities and instrumentation 7. Environment, health and safety 8. Education and societal dimensions 484M 342M 402M 77M 101M 203M 117M 35M
Nanomanufacturing Processes must work at a commercially relevant scale Cost is a key factor Must be reproducible and reliable EHS under control Nanomanufacturing includes top-down and bottom-up techniques, and integration of both Must form part of a value chain
Advances in the Last Decade: Nanoparticle Synthesis The availability of a range of new nanostructures has been facilitated by synthetic control over composition, size and shape. Nikoobakht, B. et al. Chem. Mater , Xia, Y. et al. Angew. Chem. Int. Ed , 60. Yu, Y. et al. J. Phys Chem. C , Millstone, J. E. et al. J. Am. Chem. Soc , Niu, W. et al. J. Am. Chem. Soc , 697. Zhang, J. et al. J. Am. Chem. Soc ASAP.
Advances in the Last Decade: Superlattice Formation and Assembly of Nanostructures Shevchenko, E. V. et al. Nature , 55. Kalsin, A. M. et al. Science , 420. Entropic Drying Effects Electrostatic Assembly Directed Assembly Park, S. Y. et al. Nature , 553. Macfarlane, R. J. et al. Angew Chem. Int. Ed , 4589.
SELF ASSEMBLY with DIBLOCK COPOLYMERS Block A Block B 10% A 30% A 50% A 70% A 90% A ~10 nm Ordered Phases PMMA PS Scale set by molecular size
CORE CONCEPT FOR NANOFABRICATION Deposition Template Etching Mask Nanoporous Membrane Remove polymer block within cylinders (expose and develop) Versatile, self-assembling, nanoscale lithographic system (physical or electrochemical)
UMass Amherst/ UC Berkeley MIT UW Madison Directed self-assembly for nanoscale patterning down to 3 nm Block "A" Block "B" Advances in the Last Decade: Patterning Approaches & Device Integration Block copolymer lithography: A hierarchical-friendly method Block copolymer lithography: A hierarchical-friendly method S. Park, et al. Science , I. Bita, et al. Science , 939. Y.S. Jung, et al. Nano Lett , K. Galatsis, et al. Adv. Mater , 769.
Scanning probe-based lithographies Nanoimprint lithography Many approaches for controlling the position of materials on surfaces have been developed in the last decade. Microcontact printing Inkjet printing Nie, Z et al. Nature Nanotech , 277. Advances in the Last Decade: Patterning Approaches & Device Integration
U. Texas Austin Korea/Japan/Singapore Collaboration graphene on copper Major Advances in the Last Decade: Advanced Manufacturing Roll-to-roll production of graphene for transparent conducting electrodes X. Li, et al. Science , 1312 S. Bae, et al. Nature Nanotech , 574. Replaces indium tin oxide
NanoMFG Processes Materials Metrology Workforce EHS Information Tools Education Standards Economic Nanomanufacturing Enterprise (Science-based) To create nanomanufacturing excellence, we must attend to all parts of the value chain.
Important Strides in Nano Environmental, Health, and Safety (EHS) NIOSH: "Approaches to Safe Nanotechnology" -Emphasizing effective control banding -Now an ISO standard NIH: Nano Health Enterprise Initiative DuPont/EDF: Nano Risk Framework ACS: Lab Safety Guidelines For Handling Nanomaterials Lockheed-Martin: Enterprise-wide Procedure for Environmental, Safety and Health Management of Nanomaterials Standards: Many ISO standards on EHS are being developed
NSF Centers Dedicated to Nano EHS University of California Center for the Environmental Implications of NanoTechnology Duke Center for the Environmental Implications of NanoTechnology (CEINT) Rice University Center for Biological and Environmental Nanotechnology Components within other centers (including at UMass) Other Federal EHS Activities National Institute for Environmental Health Science NIH Nanomaterials Characterization Laboratory NIOSH EPA FDA Industrial EHS Testing
An open access network for the advancement of nanomanufacturing R&D and education –Cooperative activities (real-space) –Informatics (cyber-space) Mission: A catalyst -- to support and develop communities of practice in nanomanufacturing.
"Nanoinformatics" Nanotechnology meets Information Technology The development of effective mechanisms for collecting, sharing, visualizing, modeling and analyzing data and information relevant to the nanoscale science and engineering community. Nanoinformatics 2020 Roadmap publication The utilization of information and communication technologies that help to launch and support efficient communities of practice. Available from internano.org
Nano-informatics: Some Major Nanotech Research Communities Nanomanufacturing Environmental, Health & Safety Fundamental Research Societal Impact Modeling & Simulation National Infrastructure Health & Life Sciences Metrology Commercialization Education Energy Materials