Smart materials, including autonomic materials, self-repairing plastic products and smart polymers for biomedical applications- sense changes in the surrounding environment and respond predictably. They hold immense potential across a wide range of industries. Piezoelectric materials, which are useful in the production and detection of sound, generation of high voltages, electronic frequency generation, microbalances and ultra fine focusing of optical assemblies, are expected to be among the fastest growth areas with a major portion of the overall market, according to Frost & Sullivan findings.
Smart polymers are materials composed of polymers that respond in a dramatic way to very slight changes in their environment. These synthetic polymers are potentially very useful for a variety of applications like biotechnology, biomedicine, textiles, aircraft building, etc. Smart polymers are becoming increasingly more prevalent as scientists learn about the chemistry and triggers that induce conformational changes in polymer structures and devise ways to take advantage of, and control them. New polymeric materials are being chemically formulated that sense specific environmental changes such as temperature, presence of water, pH, the presence/intensity of light, etc, in biological systems, and adjust in a predictable manner, making them useful tools for drug delivery or other metabolic control mechanisms. The main properties of smart polymers are that they are strong, flexible, easy to colour, easy to mould and tough. An ever increasing spectrum of smart polymers based on various stimulus/adaptive property combinations is being developed to satisfy a growing range of applications in automotive, aerospace, medical, consumer, industrial and other market sectors.
Several approaches have been taken by scientists for their development. They are:
• Evolutionary morphologies of block copolymers
• Additives like magnetic oxide powder
• Thermochromic and photochromic pigments/dyes
• Stabilization of networks crosslink in a stretched state.
• Polymer alloys
Reversibility or irreversibility is of primary consideration. Reversible materials can operate multiple cycles of response/adaptation to a stimulus, whereas irreversible materials must be reset to repeat their reaction to a new cycle of stimulation. Irreversibility allows traceability of a history. An irreversible thermochromic polymer indicates that a temperature threshold has been exceeded during transportation, storage, or other activity. Reversibility makes it possible to use the same device multiple times.
Aircrafts suffer 'wear-and-tear' over the lifetime of a mission causing cracks to build up, weakening the aircraft. Advanced composite materials are susceptible to many forms of damage including impact damage which results in a reduction in strength, elastic modulus, structural durability and overall damage tolerance. Extremes of temperature can cause small cracks to open in the spacecraft superstructure, as can impacts by micrometeoroids. Self-healing composites, which take a bio-inspired approach to address this problem, offer many exciting engineering possibilities, thus reducing the cost of orbiting spacecraft and enabling more distant missions. Modern aircraft will also benefit from development of this technology offering the ability to self-repair aircraft skins damaged from punctures from hail, birds, ground damage, and fatigue failure.
Automotive makers are emphasizing on 'smart material' technology in hopes of advancing shape memory polymers to make automotive subsystems that can self-heal when damaged, or can be designed to change color. Shape memory material 'first generation' applications being tested include:
• Automatically adjusting air vents that let in more air as the engine heats up
• Aerodynamic front air dams that retract when not required
• On demand rear spoiler
• Interior grab handle that automatically unfolds to facilitate vehicle entry
• More accessible engine hood, door latch, glove compartment releases
• Smart emergency brake release
Advances in noninvasive surgery are a key driver in the application of smart polymers such as SMP use in 'smart' expandable stents and self-tying sutures.
As per Research and Markets- in 2004, the global market for electrically enabled smart fabrics and interactive textile (SFIT) technologies was worth US$248 mln. By 2008 it is expected to be worth US$485.6 mln, representing a compound annual growth rate of 18%. SFIT technology has advanced significantly in recent years. Novel polymers, when integrated into textiles, provide a range of interactive properties such as electrical conductivity, ballistic resistance and biological protection. In the future, there will be a need for even more materials whose properties alter in response to external stimuli. The global market for smart fabrics and interactive textiles is projected to reach US$1.31 bln by 2012. The use of smart polymers in creating a seamless integration between electronics and fabrics will drive the adoption of electro-active smart fabrics in future applications in the military, consumer, medical and industrial markets. The global market for electro-active polymer (EAP) actuators and sensors reached US$15 mln in 2008 and is projected to grow to US$247 mln by 2012.
(Source Courtsey: Specialchem.com)