3 052 Nanomechanics of Materials and Biomaterials LECTURE

3. 052 Nanomechanics of Materials and Biomaterials LECTURE # 1 : INTRODUCTION TO NANOMECHANICS Prof. Christine Ortiz DMSE, RM 13 -4022 Phone : (617) 452 -3084 Email : cortiz@mit. edu WWW : http: //web. mit. edu/cortiz/www

Basics of Nanotechnology “Nanostructure” Broad Definition : Specific Definition : “Molecular Manufacturing” Electron-microscope image of the world's smallest guitar, based roughly on the design for the Fender Stratocaster, a popular electric guitar. Its length is 10 millionths of a meter-- approximately the size of a red blood cell and about 1/20 th the width of a single human hair. Its strings have a width of about 50 billionths of a meter (the size of approximately 100 atoms). Plucking the tiny strings would produce a high-pitched sound at the inaudible frequency of approximately 10 megahertz. Made by Cornell researchers with a single silicon crystal, this tiny guitar is a playful example of nanotechnology, in which scientists are building machines and structures on the scale of billionths of a meter to perform useful technological functions and study processes at the submicroscopic level. (http: //www. news. cornell. edu/science/July 97/guitar. ltb. html, Dustin W. Carr and Harold G. Craighead, Cornell. ) Readings : 1. "There's Plenty of Room at the Bottom, " Richard P. Feynman's Classic Nanotechnology Talk (1959, APS-Caltech); 2. “Engines of Creation : The Coming Era of Nanotechnology, ” K. Eric. Drexler, Anchor Books, Doubleday, 1986 (Chapter 1)

Nanostructured Materials (*http: //www. rpi. edu/dept/materials/COURSES/NANO/crawford/index. html) Bone Self-Assembling Monolayer Nanoporous Alumina Membrane

Nanostructured Materials “Bottom-Up Manufacturing” “Top-Down Manufacturing”

What is Nanomechanics ?

Summary of Length Scales (m) hemoglobin 6. 6 nm Biological Sciences quark electron atomic nucleus proton, neutron width of DNA, small globular proteins 2 nm atomic radii covalent bond 0. 1 nm smallest observable feature length of a cell of human eye, blue whale 50 mm thickness of human hair height of bacteria, Mt. Everest height of a internal grain of 8848 m human being organelles sand 1 m 1 mm size of virus of a bee size of the universe diameter of the earth 10 -18 10 -16 10 -14 10 -12 10 -10 10 -8 10 -6 10 -4 10 -2 100 102 104 106 1025 Materials Sciences size of C 60 molecule, diameter of carbon nanotube, suprmolecular chemistry, colloidal particles, nanolithography microelectro length crystal mechanical integrated length of a height of of the grains systems Boeing 767 NYC circuit Great Wall (MEMS), airplane World Trade of China chip radius of micro-contact Center traditional printing, AFM probe tip man-made integrated materials and circuit structures transistor

WHY STUDY NANOMECHANICS ? THREE EXAMPLES FROM BIOLOGY

Inflammatory Response : Cell Rolling and Adhesion

Muscle Elasticity (*MARSZALEK, et. al Nature 402, 100 - 103 (1999)) Nebulin SARCOMER Actin E Myosin (*Cell and Molecular Biology, G. Karp) TITIN

Packing the Genome DNA (*FEBS Lett. 371: 279 -282) simulation

Packing the Genome http: //gened. emc. maricopa. edu/Bio/BIO 181/BIOBK/Bio. Book. CELL 2. html

WHY STUDY NANOMECHANICS ? THREE EXAMPLES FROM MATERIALS SCIENCE

Performance of Computer Hard Disks http: //talke 08. ucsd. edu/index/disk. html

Computer Head-Disk Interface http: //talke 08. ucsd. edu/index/disk. html suspension arm recording head 2 mm head flexure surface roughness 30 -60 nm slider read / write element hard disk flying height 30 -60 nm

Properties of Colloids (*http: //wintermute. chemie. uni-mainz. de/coll. html) Silica sphere glued to an AFM-probe tip

Macroscopic Mechanical Properties of Materials Less Disorder More Disorder random coil Entropy - a natural law that expresses the driving force towards disorder F Fchain r Fchain F F Rubber Elasticity s Non-Linear, Entropic Elasticity of Polymer Networks l F

A Typical High-Resolution Force Spectroscopy Technique : General Components displacement detection system high-resolution force transducer d computer probe sample high-resolution displacement control sensor output z • controls system • performs data acquisition, display, and analysis