We have all been taught that there are four states of matter: Solid, Liquid, Gas and Plasma, but some states of matter cannot be defined by one of these four. One of which is liquid crystals. These crystals have properties of both liquids and solids. They physically flow like liquids, but they also share the characteristics of crystalline solids. There are also multiple types of liquid crystals with their different phases. Since they have so many properties, it's no wonder how much we use them today. They can be found in most of today's electronic and technological devices. The first discovery of liquid crystals is believed to have occurred about 150 years ago, but was not clearly specified until about 50 years ago. The first discovery was made around 1850 by Virchow, Mettenheimer and Valentin. They were studying a certain type of nerve fibers and one day they realized that when they were left in water, they formed a fluid substance that, when observed using polarized light, would exhibit strange behavior. They did not realize that this behavior was a new phase between a liquid and a solid, but they are credited with the first observation of liquid crystals. Some time later, in 1877, Otto Lehmann used a polarizing microscope with a heated stage to study the phase transitions of different substances. He discovered that one of the substances he was testing would change from a clear liquid to a cloudy liquid before crystallizing. He didn't think of it as a new phase, but he thought it was an imperfect transition from the different phases from liquid to crystal, or an undefined phase. A year later, in 1888, Reinitzer conducted experiments similar to those mentioned above and was the first to claim that this cloudy fluid was a new phase of matter…half of paper…boards. Other biological uses include DNA from cell membranes and proteins. The liquid crystal phase plays an important role in our life and contributes to the life of living beings. It also contributes to everyday technologies. This is an important phase of matter that we will continue to use every day and continue to use for the benefit of our civilization to improve for the better. Works Cited http://en.wikipedia.org/wiki/Liquid_crystal http://www. lci.kent.edu/lc.html#Descriptionhttp://electronics.howstuffworks.com/lcd.htmhttp://www.encyclopedia.com/topic/liquid_crystal.aspxhttp://www.eng.ox.ac.uk/ lc/introduction/intro_1.htmlhttp://www.personal.soton.ac.uk/tim/lc.htmlhttp://plc.cwru.edu/tutorial/enhanced/files/LC/intro.htmhttp://74.125. 47.132/search?q=cache:FXC5vOAN7woJ:invsee.asu.edu/nmodules/liquidmod/good.html+uses+for+liquid+crystals&cd=4&hl=en&ct=clnk&gl=us