Sensors: Polymer Materials with Integrated Deformation Sensors

Case Western Reserve University, Cleveland OH

Investigators

Abstract

This Sensors and Sensor Networks (Sensors) Individual Investigator (SII) grant provides funding for the development of processes that allow the production of new polymer materials with integrated mechanical deformation sensors. The targeted materials are based on the incorporation of small amounts of fluorescent dyes into conventional polymers. The sensing mechanism relies on the formation of nanoscale aggregates of these dyes in the polymer matrix. It further exploits that mechanical deformation can transform the nanophase-separated systems into molecular mixtures. Because the dye molecules are tailored to form excimers when aggregated, this phase transition is concomitant with a shift of the dyes' fluorescence color. This experimental research program encompasses (i) the development of fluorescent sensor molecules, which are rationally designed for the targeted sensing principle, (ii) the investigation of the phase behavior of blends of these sensor molecules and selected, technologically relevant polymers, and (iii) the development of protocols, which allow for the production of adequate polymer/dye nanocomposites by conventional melt-processing techniques. To demonstrate the value of the novel sensing scheme, a complete system consisting of material, optical detection module, and data analysis interface will be assembled. The primary goals of this work are to determine how polymer/sensor nanocomposites can be reliably produced by conventional fabrication techniques, and how their supramolecular architecture, and therewith fluorescence color, changes as a function of external stimulus. If successful, the results of this research will lead to a predictive understanding of the thermodynamic and kinetic aspects of nanoparticle (de)formation in blends of polymers and low-molecular, organic guest molecules. If successful, the resulting knowledge may provide a broad intellectual basis for the future design, processing and application of advanced functional nanomaterials. The new platform of polymers with built-in sensors has the potential to enable a variety of technologically relevant applications that range from early failure indicators in structural materials to tamper-resistant packaging.