Polymer-based photonic sensors for physicochemical monitoring

摘要

The ability to engineer polymer materials that have special response to external factors as well as to incorporate nano- and/or micro- materials in these polymer matrices make these materials perfect candidates for physicochemical sensors. The incorporation of the nano-/micro-materials help the polymer materials become more sensitive to a variety of external factors. Different polymer designs for the detection of humidity, alcohols and hydrocarbons are described. Special diffractive photonics structures are implemented to offer increased sensitivity to physicochemical changes. The final photonic sensor design is based on an optimization of chemical as well as optical design. The chemical polymer designs are based on selecting and synthesizing the appropriate polymeric structure that will facilitate interaction with the analyte, through a number of physical and chemical processes (adsorption, solubilization, entrapment, coulombic interaction and hydrogen bonding). These functions are determined by the chemical and structural features of the polymer used i.e. functional groups, glass transition, porosity, etc. In the case of polymer/nano- and/or micro-inorganic hybrid materials, interactions of the polymer matrix with the inorganic component(s) and dispersion of the nanomaterials within the matrix have to be taken into account. Suitable photonic interfaces based on transmissive and/or diffractive techniques are designed to provide the medium with interface tailoring and interrogation methodologies. Novel photonic information processor prototype devices based on free space configurations are demonstrated to extract/recover the captured information from the sensing material. The advantageous characteristics of the presented integrated sensor are the fully reversible behavior, at ambient operating conditions, without the need for additional heating or light exposure.