Two University of Colorado Boulder chemical engineering PhD students have earned prestigious 2022 National Defense Science and Engineering Graduate (NDSEG) Fellowships.
Kristin Lewis and Alexis Phillips are being recognized with the Department of Defense program, which provides full tuition coverage and a stipend to honorees for up to three years.
The pair are among 165 students nationwide receiving the honor this year. The Congressionally-chartered program is designed to promote promising young U.S. scientists and engineers studying in disciplines of military importance.
Find out more about their research below.
Alexis Phillips
3rd Year Chemical Engineering PhD Student
Advisor: Tim White
Lab: Responsive and Programmable Materials Group
My research is largely focused on developing and optimizing reconfigurable optical materials. I explore the synthesis, response, and device utility of stimuli-responsive, selectively reflective cholesteric liquid crystal elastomers (CLCEs). The periodic chiral nematic alignment yields selective Bragg reflection in these materials. The reflection wavelength is dependent on the pitch length which can be altered by applying a stimulus. My goal is to realize color change in fully solid CLCEs by manipulating the selective reflection using an electric field as a stimulus. The electro-optical reconfiguration in these materials could be used to vary transmission/reflection, attenuate undesired light in windows, and create tunable optical filters in the visible or IR regions of the spectrum.
Kristin Lewis
3rd Year Chemical Engineering PhD Student
Advisor: Tim White
Lab: Responsive and Programmable Materials Group
My research is focused on improving the stimuli response of liquid crystalline elastomers (LCEs) through the incorporation of hydrogen bonds within the liquid crystal mesogens themselves. LCEs are commonly used as actuators for applications such as soft robotics but are currently limited by their continuous phase transitions and inefficient use of input energy. My work utilizes supramolecular liquid crystalline dimers that dissociate with increasing temperature and strain leading to more rapid thermotropic phase transitions and sharper actuation responses in LCEs. I will be extending upon this research by elucidating the effect of hydrogen bonds on the network phase behavior, developing new polymer chemistries to improve these supramolecular LCEs, and introducing photoresponsive supramolecular units to also enhance the phototropic response of LCEs. My ultimate goal is to realize quasi-1st order (subcritical) phase transitions in LCEs. These efforts would enable rapid and programmable shape morphing materials that are sensitive to heat or light and highly applicable towards DoD applications.