“Nanobiotechnology and Biomimetics” MSE 405/505 Nanotechnology Principles Don Haynie 5th and 7th April 2004 Guiding principle Structure determines function “Emerging areas” – Biosystems at the nanoscale – Nanoscale structures, novel phenomena, and quantum control – Device and system architecture – Design tools and nanosystems-specific software – Nanoscale processes in the environment – Multi-scale, multi-phenomena modeling and simulation at the nanoscale – Manufacturing processes at the nanoscale – Studies on the societal implications of nanoscale science and engineering Biomimetics Biomimetics and nanotechnology • Diatoms are about 10 microns long • They exist in countless numbers throughout the world, helping to make up the base of the food web • They are responsible for about a quarter of the world's total carbon sequestration • In fossilized form, they're the source of diatomaceous earth and the ingredients in all-natural insecticides, concrete, and animal feed. • Diatoms are photosynthetic • They make their shells out of silica dissolved in seawater • Derived from the element silicon, silica is the compound used to make glass • Silica has also become the raw material used in the burgeoning field of nanotechnology • Diatoms inspire technology development by mimicry Diatoms – low resolution Diatoms – high resolution Self-assembly: the simplest and most prevalent theme of nature? –Lipids assemble into sheets to form cell membranes –Proteins assemble into functional enzymes, cellular ‘sensors’, and fibers –DNA assembles in double strands, enabling replication and transmission of genetic information Dominant forces • Thermal energy – First Law of thermodynamics – Second Law of thermodynamics • Electromagnetism – Maxwell’s equations • Quantum mechanics – Schrödinger equation A challenge • The fabrication of ever-smaller components – involving micro- and increasingly nanofabrication – which bear the information to assemble into predetermined configurations. • The individual building blocks must carry not only the information to find and interact with their neighbors, but also the information to assemble into materials of hierarchical structure - one of the “success strategies” of natural materials. • The ability to build micro- and nano-scale components with imprinted information that can self-assemble into hierarchical structures will launch a new area of engineering. The materials needed to do this are polypeptides. Hierarchical structure of living matter • Nervous system • Vasculature •Tree • Muscle Geometry of art and life Hierarchical structure of muscle Sarcomere Myosin Actin Cal Tech Web site Example: “Mechanically-driven ATP synthesis by the F1-ATPase” Published 29th Jan. 2004 in Nature ATP • The main biological energy currency • Synthesized from ADP and inorganic phosphate • “Manufactured” by ATP synthase • Synthesis consumes energy Four stages in ATP synthesis H+ F1 F0 H+ Generation of rotation in F0 F1 portion of ATP synthase • Functions as a rotary molecular motor • γ-subunit rotates against the surrounding α β 3 3 subunits at about 50-100 Hz • Hydrolyzes ATP in three separate catalytic sites on the b-subunits • Rotation of the γ-subunit is driven by proton flow through associated F0 portion of ATP synthase; this is believed to lead to ATP synthesis in vivo. Further particulars •F1-ATPase rotates with discrete 120° steps. • The efficiency of chemical-to-mechanical energy conversion approaches 100 %. Approach γ • Attach a magnetic bead the -subunit of isolated F1 • Allow F1 to adsorb on a glass substrate • Test whether chemo-mechanical coupling in the F1 motor is completely reversible, i.e. whether a vectorial force (torque) working at a particular point on a protein machine can influence a chemical reaction occurring in physically remote catalytic sites and drive a reaction far from equilibrium • Manipulate rotary angle of γ-subunit • Monitor direction of rotation by increase in ATP production (luciferin-luciferase chemiluminescence detection on ATP hydrolysis) α β γ 3 3 is the minimal subcomplex of F1 that shows ATP-catalyzed rotation γ-subunit β-subunits biotinylated Attached to at two surface by engineered engineering cysteines polyhistidine at N- Glass surface terminus Streptavidin binds biotin effectively irreversibly Medium contains ADP and phosphate as Substrates and the luciferin-luciferase system Possible future directions • Self-healing in tubes by mimicking blood-clotting • Self-healing of electrical wires by mimicking wound (blood vessel) healing • Self-assembly of chiral materials, mimicking certain plants and snail shells • Self-assembly of mesoscale objects, mimicking DNA hybridization • Templated self-assembly mimicking chaperones • Self-assembly of diodes to form displays • Self-assembly of electrical components, which are arranged in a string, mimicking protein folding • Self-”folding” of microcomponents into three-dimensional building blocks.