Introdução à Nanomecânica de Materiais e Biomateriais: História e Definições, Notas de estudo de Engenharia de Produção

Baixe Introdução à Nanomecânica de Materiais e Biomateriais: História e Definições e outras Notas de estudo em PDF para Engenharia de Produção, somente na Docsity! 3.052 Nanomechanics of Materials and Biomaterials 02/06/06 Prof. C. Ortiz, MIT-DMSE I LECTURE 1 : INTRODUCTION TO NANOMECHANICS Outline : NANOTECHNOLOGY / NANOMECHANICS DEFINITIONS ............................................................................... 2 WHY IS NANO INTERESTING? ............................................................................................................................... 3 HISTORY OF NANOTECHNOLOGY/NANOMECHANICS : TIME LINE............................................................ 4 The First Talk on Nanotechnology: "There's Plenty of Room at the Bottom" - Richard Feynman (1959) ............. 5 Moving Individual Atom s with the Scanning Tunneling Microscope - Don Eigler (1990) ..................................... 6 Imaging Individual Biomacromolecules with the Atomic Force Microscope (2003) ............................................... 7 Dip Pen Nanolithography : "There's Plenty of Room at the Bottom" - 40 years later-Chad Mirkin (1999) ............. 8 NANOFABRICATION /NANOSTRUCTURED MATERIALS: "BOTTOM-UP" vs. "TOP-DOWN".................... 9 NANOMECHANICS.................................................................................................................................................. 10 Concept of a Continuum .......................................................................................................................................... 10 Subcategories : Contact vs. Noncontact.................................................................................................................. 11 Objectives: To establish the terminology, history, broad concepts, and motivation for course Readings: Course Reader Documents 1-5 Multimedia : Listen to "Tiny Machines" by Richard Feynman, plus Introduction mp3 by Prof. Ortiz 1 3.052 Nanomechanics of Materials and Biomaterials 02/06/06 Prof. C. Ortiz, MIT-DMSE NANOTECHNOLOGY / NANOMECHANICS DEFINITIONS Nanotechnology : "Νανο" derives from the Greek word for dwarf. Technologies dealing with characteristic length scales 1-100 nanometer (1 nm) = 1*10-9 m (one billionth of a meter) →atoms molecules, cells. FactorSymbolPrefix 10-1ddeci 10-15ffemto a p n μ m c k M G 10-18 10-12 10-9 10-6 10-3 10-2 103 106 109 atto pico nano micro milli centi kilo mega giga Molecular Manufacturing / Nanofabrication : Fabrication / modification of structures with nm-scale precision Nanomechanics: Subset of the field of nanotechnology involving nN-scale forces or nm-scale displacements Nanostructured Materials : materials where fundamental constituents are nm-sized Less than a nanometer : individual atoms are up to a few angstroms or up to a few tenths of a nanometer in diameter Thousands of nanometers : Biological cells, like red blood cells, have diameters in this range One nanometer : Ten shoulder-to-shoulder hydrogen atoms (blue balls) span 1 nanometer. DNA molecules are ~ 2.5 Billions of nanometers : A two meter tall male A Million nanometers : The pinhead sized patch of this thumb (circled in black) Adapted from a Report by the National Science and Technology Council (NSTC) Committee on Technology, The Interagency Working Group on Nanoscience, Engineering and Technology (IWGN) (1999) 2 3.052 Nanomechanics of Materials and Biomaterials 02/06/06 Prof. C. Ortiz, MIT-DMSE THE FIRST TALK ON NANOTECHNOLOGY : "There's Plenty of Room at the Bottom" (1959) Richard P. Feynman December 29th 1959 (41 y.o.) American Physical Society Meeting (CalTech) : theoretical physicist "Nanotech Prophet" -enormous amounts of information can be carried in an exceedingly small space -scaling down devices requires new designs and does not violate any fundamental laws of physics; look at biology - army of "slave hands" : nanomanipulators -"physical synthesis" as opposed to "chemical synthesis" Challenges : miniaturization of the computer, direct visualization at the nanoscale, Encyclopedia Brittanica on the head of a pin, construct a 1/64 cubic inch motor Multimedia : Watch the movie "Tiny Machines" by Richard Feynman (1988) Cool book to read "Surely You're Joking Mr. Feynman" Image removed due to copyright restrictions. Portrait photo of Richard Feynman playing bongo drums. 5 3.052 Nanomechanics of Materials and Biomaterials 02/06/06 Prof. C. Ortiz, MIT-DMSE MOVING INDIVIDUAL ATOMS WITH THE SCANNING TUNNELING MICROSCOPE (STM)- 30 Years after Feynaman (1990) D. M. Eigler & E. K. Schweizer IBM Almaden (NATURE VOL 344 5 APRIL 1990) Move and position individual atoms on a metal surface using a scanning tunneling microscope tip. Writing one atom at a time with Xe atoms on a Ni (110) surface, IBM scientists could actually fit the Encyclopedia Brittanica on a space the size of a pin head. The STM microscope was cooled to 4 K, in an ultra-high -vacuum system, and the STM tip speed was 0.4 nm/sec. At that speed they could have completed the job in about 87,000 years. - The challenge is how to build macroscopic structures in a reasonable time frame and how to make functional structures. 5 nm Images removed due to copyright restrictions. 1) 3-D image of letters “IBM” produced by a series of points. 2) Photo of the STM tip. 6 3.052 Nanomechanics of Materials and Biomaterials 02/06/06 Prof. C. Ortiz, MIT-DMSE IMAGING INDIVIDUAL BIOMACROMOLECULES WITH THE ATOMIC FORCE MICROSCOPE (2003) Ng, Ortiz et al. 143 Journal of Structural Biology 2003 242- individual cartilage aggrecan macromolecules Courtesy Elsevier, Inc., http://www.sciencedirect.com. Used with permission. -Relevance to disease (e.g. osteoarthritis), diagnostics, and tissue engineering 7 3.052 Nanomechanics of Materials and Biomaterials 02/06/06 Prof. C. Ortiz, MIT-DMSE NANOMECHANICS : CONCEPT OF A CONTINUUM ● A continuum is a region of space filled with continuous matter that has continuous properties→ ignore heterogeneities (e.g. pores) ● Approximation that breaks down at small enough length scales depending on the material structure. 10 Figure by MIT OCW. 3.052 Nanomechanics of Materials and Biomaterials 02/06/06 Prof. C. Ortiz, MIT-DMSE NANOMECHANICS SUBCATEGORIES 1. Noncontact : High Resolution Force Spectroscopy, surface forces measurement (e.g. electrostatics, van der Waals forces, etc.) Separation distance ~ nm Interaction force ~ nN Sample topics covered in course : ● heparin biosensor ● single protein and DNA tensile testing ● sacrificial bonding in biological materials ● nanomechanics of cell surfaces -lipid bilayers ● molecular origins of biocompatibility ● electrostatic interactions in cartilage and the origins of osteoarthritis 2. Contact : Nanoindentation, single cell tensile testing (e.g. elasticity, plasticity, → dislocations) etc. 11 0.5 μm 8 μm 0.9 μm c-axis Sample topics covered in course : ●tensile testing of diseased cells- malaria ● nanogranular friction in bone ● nanomechanics of seashells Courtesy of Benjamin Bruet and Journal of Materials Research. Used with permission.