TABLE OF CONTENTS Gregory P. Crawford and Scott J. Woltman
Imagination is more important than knowledge. For knowledge is limited to all we now know and understand, while imagination embraces the entire world, and all there ever will be to know and understand.
Albert Einstein (1879 1955)
For the past 40 years, liquid crystals have been associated with visual displays, known as liquid crystal displays, or LCDs. Today, liquid crystals dominate the worldwide market in flat panel displays, from laptop screens to desktops and more recently penetrating the large area television market. Because of the maturing nature of the field, researchers trained in liquid crystal science and technologies are now looking forward to intriguing new applications which can utilize the many unusual and powerful electro-optic properties of liquid crystals. This book is focused on one such new application area biomedical engineering. Before engaging in the many new applications liquid crystals may enable, such as medical displays, spectrometers, sensors, actuators, and so on, this chapter offers a brief overview of their basic properties and applied characteristics.
The term liquid crystal describes a state of matter that is intermediate between an isotropic liquid and a crystalline solid. Since their discovery in the late 19th century by Reinitzer (1888) and Lehmann (1889), there have been thousands of compounds identified to exhibit this unusual phase of matter the liquid crystalline or mesogenic phase. The terms liquid crystal and mesogen are used synonymously. The underpinning prerequisite for liquid crystallinity is that the molecule...
