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Introduction to Nanomechanics (Spring 2012). Martino Poggio. Preliminary Logistics and Introduction. Course outline and expectations; What is nanomechanics ? Why study nanomechanics ?. People. Course Leader/Lectures: Martino Poggio Teaching Assistants/Exercise Sessions:
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Introduction to Nanomechanics(Spring 2012) Martino Poggio
Preliminary Logistics and Introduction Course outline and expectations; What is nanomechanics? Why study nanomechanics?
People • Course Leader/Lectures: • Martino Poggio • Teaching Assistants/Exercise Sessions: • Michele Montinaro • FeiXue • Gunter Wüst • Jonathan Prechtel Introduction to Nanomechanics
Format and requirements • Language: English • Prerequisites: Physics III; course-work in solid- state physics and statistical mechanics • Lectures: 10-12 on Tues. (21.02-29.05.2012) • Exercise Sessions: 13-14 on Wed. • Assignments: exercises and reading of current papers • Final paper: 4-5 page report on significant experimental paper due on 29.06.2012 • Grading: Pass/fail Introduction to Nanomechanics
Literature • Foundations of Nanomechanics, A. N. Cleland (Springer, 2003) • Fundamentals of Statistical and Thermal Physics, F. Reif (McGraw-Hill, 1965) • Original papers from Nature, Science, Physical Review Letters, Applied Physics Letters, Review of Scientific Instruments, Physics Today, etc. Introduction to Nanomechanics
Website http://poggiolab.unibas.ch/NanoMechSpring2012.htm • Overview • Format and Requirements • Schedule • Lecture content • Exercise session • Documents (PDF) • Optional reading • Documents (PDF) Introduction to Nanomechanics
http://poggiolab.unibas.ch/NanoMechSpring2012.htm Introduction to Nanomechanics
http://poggiolab.unibas.ch/NanoMechSpring2012.htm Introduction to Nanomechanics
What is nanomechanics? • Well… it’s the study of the mechanical properties of very very small things • A nanometer is 10-9 meters 1 nm = 0.000000001 m 100,000 nm ≈ diameter of a human hair 1 nm ≈ diameter of 10 atoms Introduction to Nanomechanics
Size scales Visible light 0.4 - 0.8 mm Basel DNA 2.5 nm The sun 1.4 Gm H atom 50 pm 1.2 Mm Proton 1.75 fm Average man 1.75 m Matterhorn 1.0 km Lecce BIG small Red blood cell 10 mm 109 m 106 m 103 m 100 m 10-3 m 10-6 m 10-9 m 10-12 m 10-15 m Gm Mm km m mm m nm pm fm Dog flea 2 mm Introduction to Nanomechanics
(Macro)mechanics Nanomechanics 109 m 106 m 103 m 100 m 10-3 m 10-6 m 10-9 m 10-12 m 10-15 m Gm Mm km m mm m nm pm fm Introduction to Nanomechanics
How is nanomechanics different than (macro)mechanics? • Thermal fluctuations significantly affect the motion of small bodies • Quantum mechanical fluctuations affect the motion of even smaller bodies Introduction to Nanomechanics
Brownian motion Fat droplets suspended in milk through a 40x objective. The droplets are 0.5 - 3.0 mm in size. Introduction to Nanomechanics
Thermal energy Particle mass Boltzmann constant Mean square velocity Temperature Introduction to Nanomechanics
Brownian motion Mean square displacement (a measure of the size of the fluctuations) Elapsed time Particle radius Viscosity of medium Introduction to Nanomechanics
Cantilever F x Spring constant Introduction to Nanomechanics
Cantilever F x Mean square displacement Introduction to Nanomechanics
1st mode Introduction to Nanomechanics
(Macro)mechanics L = 2 m w = 100 mm t = 50 mm ESS = 200 GPa xth = 0.2 pm for T = 300 K k = 78 kN/m Introduction to Nanomechanics
Nanomechanics L = 120 mm w = 3 mm t = 100 nm ESi = 169 GPa xth = 8 nm for T = 300 K k = 73 mN/m Introduction to Nanomechanics
Quantum fluctuations Zero point fluctuations Planck constant Resonant frequency Mass Introduction to Nanomechanics
(Macro)mechanics l = 2 m w = 100 mm t = 50 mm ESS = 200 Gpa r = 7.85 g/cm3 xZPF = 0.2 am xZPF = 0.2 x 10-18 m k = 78 kN/m m = 20 kg Introduction to Nanomechanics
Nanomechanics L = 120 mm w = 3 mm t = 100 nm ESi = 169 Gpa r = 2.3 g/cm3 xZPF = 0.2 pm xZPF = 0.2 x 10-12 m k = 73 mN/m m = 20 pg Introduction to Nanomechanics
Carbon nanotube m = 10-21 kg w = 2px 500 MHz xZPF = 4 pm xZPF = 4 x 10-12 m Introduction to Nanomechanics
Quantum fluctuations of a drum Lehnert, 2011 Introduction to Nanomechanics
Why study nanomechanics? • Link between classical mechanics and statistical mechanics • Link between classical mechanics and quantum mechanics • Smaller sensors are more sensitive Introduction to Nanomechanics
What is nanomechanics good for? • Smaller sensors are more sensitive! • Measurement of displacement • Measurement of mass • Measurement of force • Measurement of charge • Measurement of magnetic moment Introduction to Nanomechanics
Atomic force microscopy (AFM) Si (111) (AFM) Giessibl, 2000 DNA (AFM) 10 nm Magnetic Bits (MFM) Hamon, 2007 500 nm Folks, 2000 10 mm Introduction to Nanomechanics
Scanning tunneling microscopy (STM) Eigler, 1993 Introduction to Nanomechanics
Quantum effects Quantum of Thermal Conductance Casimir Force Measurement Decca, 2003 Schwab et al., 2000 Introduction to Nanomechanics
Weighing a single atom Zettl, 2008
Measuring a single electron spin Rugar, 2004 Introduction to Nanomechanics
Nano-magnetic resonance imaging (nanoMRI) Degen, 2009 50 nm Introduction to Nanomechanics
Cantilever Basics (statics) Introduction to Nanomechanics