SST: Collaborative Research: Capacitive Sensing for Liquid Crystal-Based Chemical and Biological Sensors

University Of Alabama In Huntsville, Huntsville AL

Investigators

Abstract

0428073 Lindquist The investigators have formed a sensor small team (SST) of electrical, chemical and biological engineers to explore capacitive sensing for liquid crystal (LC) based chemical and biological sensors. Lead by the efforts of one of the investigators on this proposal, LC systems have proven to be excellent candidates for low cost, portable, field-deployable, highly selective chemical and biological sensors. In these sensors, the molecular alignment of liquid crystal is altered by the presence of targeted chemical or biological agents. The collective behavior and high anisotropy of the LC molecules allow for the detection of extremely low levels of targeted agents. This investigator has demonstrated surface-driven orientational changes of LC molecules in both chemical and biological systems with sensitivity levels as low as ten parts per billion. In these examples, visual inspection is used to sense the deformations within the LC material. The PIs propose to change the transduction method from an optical to a capacitive technique. To exploit capacitive sensing, the PIs will bring together expertise in chemical and biological engineering from Professors Nicholas Abbott and Juan de Pablo's group at The University of Wisconsin and expertise in electrical and computer engineering from Professor Robert Lindquist's group at the University of Alabama in Huntsville. The team will take a systems approach that covers the fundamental issues of capacitive sensing in partially ordered systems, detailed dynamic modeling of the LC deformation and its impact on capacitance, optimal material and electrode designs for both chemical and biological sensors, and finally device integration issues.