Micro and Nanotechnology: An Overview Dr. Kristy M. Ainslie From Dr. Tejal Desai’s Lab, UC San Francisco June 20, 2007

Red blood cells (~7-8  m) Fly ash ~  m Human hair ~  m wide Ant ~ 5 mm Dust mite 200  m ATP synthase ~10 nm diameter 0.1 nm 1 nanometer (nm) 0.01  m 10 nm 0.1  m 100 nm 1,000 nanometers = 1 micrometer (mm) 0.01 mm 10  m 0.1 mm 100  m 1,000,000 nanometers = 1 millimeter (mm) 1 cm 10 mm m m m m m m m m m Atoms of silicon spacing nm DNA ~2-1/2 nm diameter The Scale of Things – Nanometers and MoreVisible Infrared Ultraviolet Microwave Soft x-ray Micro-technology “The Micro World” Nanotechnology “The Nano World” Head of a pin 1-2 mm

Nanoscale Fits the Molecular World One 5’5” Student (our example molecule) A 8’ desk? A 2’ 6” desk? Or a 5’ desk? Compared to what we can see, an atom scale is about a million times smaller! Imagine a desk a million times too big!

Nanomaterials Have More Atoms on the Surface Materials of the micro (1x10 -6 m) and especially nano (1x10 -9 m) size have more atom exposed on the outside then inside Volume = 18x19x1 nm 3 or 15x8x16 atoms = 1920 atoms total 976 or 51% of the atoms are at the surface Nanomaterial Volume = 3x3x0.7  m 3 or ~4 million atoms total 976 or 4% of the atoms are at the surface Micro-scaled Material 1x1x1 cm 3 A 1x1x1 cm 3 cube will have % of the atoms exposed to the surface

Surface Atoms Interact more with the Environment Energy comes from the environment to affect molecular nature. Since more molecules are on the surface, the affect is more pronounced. Temperature Heat Cold Light The forms of energy that affect us in the environment can affect molecules. Sound

Nanotechnology has mechanical applications Quantum corral of 48 iron atoms on copper surface positioned one at a time with an STM tip Corral diameter 14 nm MicroElectroMechanical (MEMS) devices  m wide Carbon buckyball ~1 nm diameter Self-assembled, Nature-inspired structure Many 10s of nm Carbon nanotube ~1.3 nm diameter

A Stretched Out Buckey Ball Becomes a Nanotube Fullerenes (aka buckyballs) Discovered in 1985 at the University of Sussex and Rice University Named after Richard Buckminster Fuller Geodesic domes (Epcot Center) Made entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube. Used for microelectrics, sensors and composite materials

MEMS MEMs: MicroElectroMechanical Systems High proportion of atom on the surface changes characteristics –electrostatics (static electricity) –wetting Can be fabricated with semiconductor fabrication technology (microchips) Made of silicon, polymer or other metals (e.g. gold, nickel, platinum) Used for sensors, computer processors, an inkject printer

Quantum Dot Colors Vary with Size Semiconductor based material Confines electron motion in three directions Releases discrete quantized energy Used in LEDs, sensing, and lasers

Nanotechnology Includes Nanomaterials Any material that has nano-scale features are termed a nanomaterialNanowires Nanoparticles Nanomembranes Nano-others

In Addition, Nanotechnology has biomedical applications Kinesin walks on Microtubule ~100  m Lab on a Chip Technology on the micron scale Biosensors Detection from DNA to Proteins 10nm-100  m Therapeutic Drug Delivery Devices 10nm-100  m DNA to Bind and Detect Proteins 10nm-100  m

DNA Atoms Small Molecules Proteins Viruses BacterialCells 100  m1x10 -4 m 10  m 1  m 100 nm 10 nm 1 nm 1 Å 1x10 -5 m 1x10 -6 m 1x10 -7 m 1x10 -8 m 1x10 -9 m 1x m The Scale of the Biological World Plant & Animal Cells

Microfluidics are Microscale Piping Smaller piping means smaller volumes of fluids are needed The area the fluid is moving in is so small, that the liquid does not mix

Biosensors Detect Analytes from Bodily Fluids Biosensors use antibody or other specific binding molecules to capture the substance of interest Output can be light, movement, an electrical signal

Lab on a Chip: Diagnosis at the Hospital Bedside Lab on a chip integrate nanomaterials, microfluidics, biosensors, microelectrics, and biochemistry

Therapeutic Delivery of Drugs Can Reduce Side-effects Small scale “pills” can be taken up by cells Adding of antibodies can be used to target sick cells Administered through IV, the skin, inhaled, orally

Micro and Nanotechnology can be used for Tissue Engineering To grow a cell needs to adhere and spread Nanomaterials can navigate cell growth Cells can adhere to nanomaterials more strongly

Nanomaterials can Change Cell Behavior Stem cells can be grown on nanomaterials The differentiation of the stem cell can be changed with nanomaterial interactions

Review of Micro and Nanotechnology Things on the nanoscale are a billion times smaller then a meter-stick. Things on the microscale are a million times smaller then a meter-stick. Higher % of molecules on the surface leads to different properties. Micro- and nano-scale materials include Buckeyballs and nanotubes Micro and Nanotechnology are on the scale of the biological world. These materials can help treat, diagnose and research diseases.

References tml Scale of Biological World – – – – – – – – – – – – – – – – Biomedical Applications – – – pg MEMs – – – – – Quantum Dots – – – – Nanomaterials – – – – – – – – – – – – – –

References Biosenors – – – – – – Therapeutic Drug Delivery – – – – – Stem Cells – – Lab on a chip – – – – – Microfluidics – – – –uxlink.rsc.org – – –