Communication for Micro Nano Robots Faculty Anita Christaline

Communication for Micro / Nano Robots Faculty : Anita Christaline. J.

UNIT 1

Micro / Nano technology • Microtechology is concerned with the implementation of miniaturization science and techniques in order to fabricate, analyse and characterise products with features at the micron scale. • Even though the typical product in microtechnology is the electronic chip, miniaturized electronic components on a common silicon substrate, • other mechanical components have also been miniaturized such as for example the micro-accelerometers for automobile airbags, micro-diaphragms for pressure sensors, micromirrors for fibre optics and microcantilevers for biosensors. • The integration of such mechanical components with associated electronic components creates the Micro-Electro-Mechanical Systems, MEMS.

Micro / Nano technology • Nanotechnology studies the physical, chemical, electrical and mechanical properties of human engineered and physical structures that possess features at the nm scale, namely from 1 nm to 1μm. • This technology is highly motivated by the biological structures of nanometre scale found in animal and plant cells. • Humans endeavour to integrate properties such as replication and its regulation by DNA and RNA, light sensing by rods and cones in chlorophyl, nanomagnetism by magnetotactic bacteria on single multifunctional devices.

Micro/nano robotic system components, products • MICRO and nano-scale robot systems have been one of the new frontiers of systems and control research field. • These robots would enable new tools and novel approaches to design, construct, and control micro and nano-scale systems. • A micro/nano-robot with overall sizes from macroscale to millimeter and sub-millimeter range • can be defined as a robotic system that can realize programmed tasks at the micro/nano-scale

Advantages • These miniature robots have unique advantages such as accessing to unprecedented and small areas, increased flexibility, functionality and robustness, and being low cost, many (swarms), adaptive and distributed.

Constraints • The locomotion and manipulation dynamics of these robots are dominated by micro/nanoscale forces and the scaling effects. • The long term target is the miniaturization of these robots down to micrometers size (such as cells as the smallest micromachines in nature).

• currently, these robots have sizes from tens of centimeters down to millimeters due to limited miniaturization and integration capabilities of available power sources, communication, control and computation schemes and tools, and coarse to fine motion mechanisms, sensors, manipulators, and actuators.

• Scaling a soccer ball down to a nano-particle size, surface to volume ratio increases inversely proportional to the length scaling factor, and therefore, surface properties and forces start to dominate bulk properties and forces. This fact is mainly called as the scaling effect.

• Nano forces Thus, the dynamics of a nano-particle are much different from a soccer ball such that the nanoparticle dynamics are dominated mainly by drag, frictional, and spring forces while nonlinear and attractive or repulsive external nano forces pull or push the particle through a long- or short range effect

• Types of Nano forces These nano-forces are intermolecular forces such as van der Waals, Casimir, capillary, hydrogen bonding, covalent bonding, Brownian motion, steric, hydrophobic, double layer, etc. forces which we neglect at larger scales

• Van der Waals force is weak, short-range electrostatic attractive forces between uncharged molecules, arising from the interaction of permanent or transient electric dipole moments. • The Casimir effect is a small attractive force that acts between two close parallel uncharged conducting plates. It is due to quantum vacuum fluctuations of the electromagnetic field. The effect was predicted by the Dutch physicist Hendrick. Casimir in 1948.

• Capillary force : force of adhesion (or cohesion) exists between the fluid and the tube concerned. This causes the fluid to rise. The net adhesive (or cohesive) force acting on fluid is called capillary force. • Hydrogen bonding : a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.

• steric force : relating to the spatial arrangement of atoms in a molecule, especially as it affects chemical reactions. • Brownian motion: the erratic random movement of microscopic particles in a fluid, as a result of continuous bombardment from molecules of the surrounding medium.

• Hydrophobic force: The tendency of nonpolar molecules in a polar solvent (usually water) to interact with one another is called the hydrophobic effect. The interactions between the nonpolar molecules are called hydrophobic interactions.