Piezoelectric Molecular Crystal: The word piezoelectricity means electricity resulting from pressure and latent heat. It is derived from the Greek word piezein, which means to squeeze or press, and, ēlektron which means amber, an ancient source of electric charge.
Indian Scientists Discover New Piezoelectric Molecular Crystal
New Delhi (ABC Live India): A group of researchers from the Indian Institute of Science Education and Research Kolkata, the Indian Institute of Technology Kharagpur and RWTH Aachen University, has found a type of piezoelectric molecular crystal that is capable of autonomous self-healing.
The paper was published in the journal Science, explains the research work on piezoelectric molecular
crystals and the crystals grew that could heal themselves.
As the researchers note, self-healing materials have become the
object of intense research in recent years. Such efforts have yielded some results polymers, gels, and other materials have been developed which, when
injured, can heal themselves to some degree. To date, such successes have all
had one thing in common—they are all soft. In this new effort, the researchers
tackled a much more difficult task: finding or developing a self-healing hard
material. In this case, that meant figuring out how to get a dense material, made
of molecules arranged in a regular way, to heal when ripped apart.
The published research reasoned that the inherent properties of
such crystals should lend themselves to self-healing because of their
attractive forces. After intensive trials, it was decided to use bipyrazole
organic crystals for their research, and thereafter the team grew a sample of crystals
in tiny (2mm long by 0.2mm wide) needle shapes.
Then the Researchers applied pressure on crystals to make them
break, and found that after the break, the needle regained its original shape,
meaning thereby that crystals material has piezoelectric
About the Piezoelectricity
Piezoelectricity is the electric charge that
accumulates in certain solid materials (such as crystals, certain ceramics, and
biological matter such as bone, DNA, and various proteins) in response to
applied mechanical stress.
The word piezoelectricity means electricity
resulting from pressure and latent heat. It is derived from the Greek word piezein,
which means to squeeze or press, and, ēlektron which means amber, an
ancient source of electric charge.
The Wikipedia on the History of
that the pyroelectric effect, by which a
material generates an electric potential in response to a temperature change,
was studied by Carl Linnaeus and Franz Aepinus in the mid-18th century. Drawing
on this knowledge, both René Just Haüy and Antoine César Becquerel posited a
relationship between mechanical stress and electric charge; however, experiments
by both proved inconclusive.
The first demonstration of the direct piezoelectric effect was in 1880
by the brothers Pierre Curie and Jacques Curie. They combined their knowledge of
pyroelectricity with their understanding of the underlying crystal structures
that gave rise to pyroelectricity to predict crystal behavior, and demonstrated
the effect using crystals of tourmaline, quartz, topaz, cane sugar, and
Rochelle salt (sodium potassium tartrate tetrahydrate). Quartz and Rochelle
salt exhibited the most piezoelectricity.
A piezoelectric disk generates a voltage when deformed (change in shape
is greatly exaggerated).
The Curies, however, did not predict the converse piezoelectric effect.
The converse effect was mathematically deduced from fundamental thermodynamic
principles by Gabriel Lippmann in 1881.
The Curies immediately confirmed the existence of the converse effect,
and went on to obtain quantitative proof of the complete reversibility of
electro-elasto-mechanical deformations in piezoelectric crystals.
For the next few decades, piezoelectricity
remained something of a laboratory curiosity, though it was a vital tool in the
discovery of polonium and radium by Pierre and Marie Curie in 1898. More work
was done to explore and define the crystal structures that exhibited
This culminated in 1910 with the publication of
Woldemar Voigt's Lehrbuch der Kristallphysik (Textbook on Crystal Physics),
which described the 20 natural crystal classes capable of piezoelectricity, and
rigorously defined the piezoelectric constants using tensor analysis.
of piezoelectric Materials
Currently, industrial and manufacturing is the
largest application market for piezoelectric devices, followed by the automotive
industry. Strong demand also comes from medical instruments as well as
information and telecommunications. The global demand for piezoelectric devices
was valued at approximately US$21.6 billion in 2015. The largest material group
for piezoelectric devices is piezoceramics, and piezopolymer is experiencing
the fastest growth due to its low weight and small size.