Application of phononic crystals as liquid sensors
Principal Investigators: Prof P Kyriacou (City University London); Prof R T Villa (Escuela de Ingeniería de Antioquia, Colombia)
Researcher: Mr S Villa
Funding: Royal Academy of Engineering (RAEng) Newton Fund
Phononic crystals and metamaterials allow for unprecedented control of elastic waves propagation. This capability paves the way to new devices with novel features, including sensors with extraordinary sensitivity and small size. The material of interest is a liquid analyte confined in a cavity of a phononic crystal having a solid matrix, constitutes one component of the phononic crystal. In an application as chemical sensor the value of interest, let's say the concentration of a toxic compound in liquid, is related to the acoustic properties of the liquid in the cavity. A change in the concentration causes measurable changes in the properties of the phononic crystal. Transmission or reflection coefficients are appropriate parameters for measurement. Specifically, a resonance induced well separated transmission peak within the band gap is the most favourable feature. The sensor scheme therefore relies on the determination of the frequency of maximum transmission as a measure of concentration. Promising applications such as biomedical sensors, point-of-care diagnostics or fast screening introduce further engineering challenges, specifically when considering a disposable element containing the analyte. Other promising applications such as water quality assessments, detection of pathogens in the food industry and fluid quality analysis in the automotive industry are also very interesting and offer many possibilities to phononic crystals research. The primary objective of this research is to investigate and evaluate the application of phononic crystals as liquid sensors by developing a systematic analysis of the main characteristics that play a role in band gap generation and the development of a sensing system.