The Fourth State of Matter: Liquid Crystals Grant Explores New Possibilities

The average person spends about three hours on their smartphone a day. In that time spent scrolling, do you ever stop to wonder what materials your phone screen is made of or why it works?

These screens are made from nematic liquid crystals, the most common form of the fourth state of matter that exists between liquid and solid.

Four Kent State University professors, Antal Jakli, Ph.D., professor of materials science; Robert Tweig, Ph.D., professor of chemistry; and Samuel Sprunt, Ph.D., and James Gleeson, Ph.D., both professors of physics, are among the first to investigate how ferroelectric liquid crystals are affected when electric fields are applied to their field of existence. The team received an $831,000 grant from the National Science Foundation to test its hypotheses.

Liquid crystals were first discovered in 1888 by Freidrich Reinsitzer and Otto Lehmann, and it is estimated that there are around 100 different phases of liquid crystals. One of these phases is ferroelectric liquid crystals, which have been theorized to exist since 1916. However, researchers were unable to actually demonstrate their existence until 2017.

Working in the Advanced Materials and Liquid Crystal Institute

Given how recently ferroelectric liquid crystals were discovered, there is still a wide field of research to be done regarding this one phase of liquid crystals.

“These materials are predicted to be used for supercapacitors,” Jakli said. “Where you can charge them and they store the energy, then you can very quickly use this energy.” 

However, the basis of Jakli and his co-principal investigators' research is to understand the electromechanical effect on ferroelectric liquid crystals. To do this, the researchers apply a voltage in audio frequency, anywhere in the range of 20 hertz to 20 kilohertz, to a film of liquid crystals. When applied, this voltage should cause the crystals to vibrate and omit sound at the frequency of the voltage.

“We are trying to find the connection between the electric field and the mechanical exertion,” Jakli said. “They could be used as speakers, which is not our main goal, but there are a lot of connections that people haven’t studied, so we’d like to see how they perform.”

To conduct this research, the investigators are utilizing facilities across Kent State’s campus in the liquid crystals, physics and chemistry departments. Some of the tools and expertise needed for this research include X-ray instruments, light-scattering technique, polarizing microscopes, chemical synthesis and dielectric measurements.