Model Experiments for Biosensor Applications: Bent-Core Liquid Crystal In a Biocompatible Thermoplastic Elastomer

MODEL EXPERIMENTS FOR BIOSENSOR APPLICATIONS: BENT-CORE LIQUID CRYSTAL IN A BIOCOMPATIBLE THERMOPLASTIC ELASTOMER

ANDREA CHARIF, JUDIT E. PUSKAS, DEPARTMENT OF POLYMER SCIENCE AND DEPARTMENT OF CHEMICAL AND BIOMOLECULAR ENGINEERING, UNIVERSITY OF AKRON, AKRON, OH 44325, USA, ANTAL JAKLI, LIQUID CRYSTAL INSTITUTE & CHEMICAL PHYSICS INTERDISCIPLINARY PROGRAM KENT STATE UNIVERSITY, KENT, OH 44242 TEL: 330-972-6198; EMAIL: ACC32@ZIPS.UAKRON.EDU

Liquid crystal (LC) elastomers combine elasticity and flexibility inherent to rubbers and the optical and electrical properties of liquid crystals, and are promising materials for applications such as electro-optics, flexible electronics and actuator technologies for biomedical applications. Most conventional LC elastomers have rod-like shaped LCs chemically attached to a crosslinked polymer network. In this study a bent-core LC with unusual superior flexoelectricity was dispersed in a polyisobutylene-based thermoplastic elastomer. The influence of the polymer substrate on the LC phase transitions in this novel bent-core LC elastomer (BCE) was studied using polarized microscopy and Differential Scanning Calorimetry. The electromechanical response of the BCE was evaluated through interferometric microscopy. Interestingly, it was found that applying electric field to a BCE sample can cause a change in its thickness. This response can be linked to the piezoelectricity of the LC molecules, whose polarization result in an expansion or a contraction of the sample. The response was found to be dependent on the magnitude and direction of the applied electric field.