Wonder Materials

     The periodic table of chemical elements, the blight of many chemistry students, always stands as a deep ocean that still has the most enigmatic materials deep down in its heart.  It is like a rosetta stone, the key for deciphering the chemical codes of all the matter in the world.

     Every year, material researchers and scientists around the globe become more adept at discovering and exploring the rules by which basic chemical elements can be combined into new and improved materials.   Some of their work has resulted in remarkable 'Smart' substances that respond to their environment.  These futuristic materials are superior in terms of strength, utility, and many more properties.

     The invention of a particular material has been a dream of these scientists & engineers for ages.  In the past, their discoveries or inventions were mostly the result of trial and error work.  They groped in the dark and their work followed no solid rationale or proven theories.  But now more efficient efforts have replaced the trial and error methods.  Advanced scientific understanding and sophisticated computers have boosted the modern alchemy to help carve out the "gold of new materials."

     "Chemical engineers will not be limited by existing materials.  They will be able to design the materials that they need."   This comes from Greg Olson a material scientist from Northwestern University in the U.S.

     His most ambitious project to date is known as 'Terminator-3", a strong steel composite that will have phenomenal properties of self-healing and biomimitism.  In other words, it will be able to emulate certain types of biological properties.  It is perhaps inspired from the movie Terminator 2, where the robot villain is made up of a metal that can take any shape, and can even reassemble itself after being blown up into bits.   This alloy, most likely iron based, will nearly be indestructible

     The basic idea behind developing this material comes from the research performed by Olson and his team.  They are trying to design alloys that have microscopic anatomies so that they can rearrange themselves by sealing their cracks.   Cracks could be sealed by the flow of molecular layers from their original positions to the ultramicroscopic cavities.  This is analogous to the natural phenomena of repairing fractured bones in animals. 

     Whether a material this strong and versatile can become a reality or not remains their primary challenge.  A major boost came when their research yielded certain models, a specific variety of seashells.  The seashells were comprised largely of brittle ceramic material in the form of microscopic slates.   Shells, such as Albacone, were reinforced with a kind of protein mortar.  When cracks began to form, this mortar stretched itself into ligaments that bridged the gaps and pulled the two sides together.

     These men are currently trying to repeat the same feat by combining a tin based alloy, which acts as the shell's microslate, with a "shape memory alloy" (one which deforms on heating and retains its original shape on cooling) to act as a protein mortar.  When combined, the new material begins to crack.  The shape memory alloy first bridges the structure and then, when heated, changes shape and clamps both sides of the cracks together.

     Such materials will find many applications in the aerospace and power generation sectors which rely on strong metal parts that work continuously under high stress conditions.  Further advances in this field will open doors for a series of unimaginable materials and may  revolutionize the science of material and matter. 

     As the scientists are trying to add flowing and reshaping properties of polymer to hard metals, some researchers are focused on a very specific task in this area;  combining  the properties of polymers with the electronic properties of conductors and semi conductors.  This violates the notion that polymers can only be used as insulators.  The potential impact of these new materials on the electronics industry could be profound.  A researcher at Lucent Technologies (U.S.) focusing on polymers in electronics is attempting to develop an "organic" transistor that combines the mechanical properties of plastics with the electronic properties of semi conductors like silicon.  Previously, this research was conducted using trial and error.  Then an employee, an expert in quantum mechanics, suggested an unexpected molecular arrangement that could result in the best combination of the two materials.  This molecular arrangement provides some free electrons to enhance its conductivity while, at the same time, retains polymer properties.  Lucent hopes that one day these materials will eliminate the hardness and inflexibility of semiconductors.  With flexible semiconductor, you may one day see scroll-like television screens that can be rolled up and hung anywhere like a poster.    Imagine electronic paper that can download any book, newspaper or magazine. 

     Marvin Cohen of the University of California, Berkley, U.S.,   has spent much time researching nanotubes.  Nanotubes are miniscule cylinders made of atoms of carbon, nitrogen, boron, or other materials.  They are the equivalent of microscopic chicken wire.  One type of nanotubes of particular interest is Buckminsteerfullerness (or simply buckyballs).  Atomically denoted as C-60, the latest isotope of carbon, this soccer ball shaped molecule has been the focus of many scientists ever since its discovery in the early 1990s.  Researchers believe that this material may hold very unique properties.

     While tracing the path of electron movement through a nanotube studded with various electrons by manipulating blotches (acting as tiny transistors on silicon chips), Cohen and scientist Steve Louise predicted that the nanotubes could be assembled into new types of computers.  These nanotubes can be linked together into complex networks, analogous to the linking network of neurons in a human mind.   So immense is the capacity of these nanotube networks, that according to a hypothesis, three wine bottles full of these microscopic tunnels can accommodate the entire world's computing needs. 
 
     Alex Zetti, another researcher in Cohen's group, has actually constructed a fingernail size arrangement of buckyballs in the laboratory that can receive & transmit electric signals.  However, these signals are random and relatively useless.  Zetti is optimistic that in near future, some order can be brought to his microscopic electric factory.  Nanotube computers may become a reality and change the way data is stored.

     The exploration does not stop there.  Researchers are continuing their work and scores of new materials with amazing properties are being developed.  These include optical fiber - a boon for telecommunications and piezoelectric ceramics that generate an electric charge when squeezed or bent thus they can follow electric command to expand, contract and even fly.

     These developments have enough potential to bring about a revolution that could lead the world into a new material age, just as its preceding ages of stone, bronze and iron.  A practical and non-fictitious vision is presented by James Sircus, Director of the Smart Material and Structure Research Center at the University of Maryland, College Park, U.S.  Houses and buildings made up of advanced piezoelectric ceramics could transmit signals to coordinate necessary repairs and maintenance.  An optical fiber nervous system could be fitted to dams, bridges and buildings.  This system can continuously scan for seismic vibration, excessive load, or even tiny cracks which can damage the structure.  If these can be fitted with Olson's "self healing" material, we could end up with a structure that takes care of itself.  The result would be a whole city that could think and react almost like humans. 

By: Priyarpan Srivastava, Associate Content Writer (read the author's Profile)
priyarpan@hotmail.com