A promising ultra-sensitive CO2 sensor at varying concentrations and temperatures based on Fano resonance phenomenon in different 1D phononic crystal designs

Abstract

Detecting of the levels of greenhouse gases in the air with high precision and low cost is a very urgent demand for environmental protection. Phononic crystals (PnCs) represent a novel sensor technology, particularly for high-performance sensing applications. This study has been conducted by using two PnC designs (periodic and quasi-periodic) to detect the CO2 pollution in the surrounding air through a wide range of concentrations (0–100%) and temperatures (0–180 °C). The detection process is physically dependent on the displacement of Fano resonance modes. The performance of the sensor is demonstrated for the periodic and Fibonacci quasi-periodic (S3 and S4 sequences) structures. In this regard, the numerical findings revealed that the periodic PnC provides a better performance than the quasi-periodic one with a sensitivity of 31.5 MHz, the quality factor (Q), along with a figure of merit (FOM) of 280 and 95, respectively. In addition, the temperature effects on the Fano resonance mode position were examined. The results showed a pronounced temperature sensitivity with a value of 13.4 MHz/°C through a temperature range of 0–60 °C. The transfer matrix approach has been utilized for modeling the acoustic wave propagation through each PnC design. Accordingly, the proposed sensor has the potential to be implemented in many industrial and biomedical applications as it can be used as a monitor for other greenhouse gases.

GHz surface-wave phononic crystal biosensor using a Fano resonance at the bandgap edge

“…To obtain a Fano resonance, a cavity resonance inside the PnC area coupled with bulk waves has been widely considered. 7,17) The detection target is introduced to the cavity, and thus shifts the central frequency of the Fano profile to realize the detection. Due to the extremely sharp resonance profile, the sensitivity is expected to be improved.…”

Fano resonance in one-dimensional quasiperiodic topological phononic crystals towards a stable and high-performance sensing tool

“…Heravi F. J. et al proposed a practical thermal sensor in the form of a solid/solid 1D PnC design. This innovative approach called "Ultra-sensitive one-dimensional phononic crystals temperature sensor" aims to address the low-temperature sensitivity observed in conventional periodic materials 8,9 . The potential risks associated with propanol exposure, including flammability and volatility leading to potential explosions, further emphasised the paramount importance of temperature sensors for propanol.…”

“…PnCs are artificial periodic structures characterised by their ability to regulate sound waves, and they have become pivotal in the field of liquid sensing applications owing to their remarkable properties 8,10,11 . PnCs offer a unique opportunity to efficiently manage acoustic waves because they are made up of two or more materials with different mass densities, elastic properties and sound speeds.…”

“…The central feature of PnC, the phononic band gap (Pn-BG), acts as a barrier preventing the passage of sound waves through the lattice. The interest in PnCs as sensors has increased due to recent developments in the field, particularly liquid sensing 8,12 . In the field of liquid sensing, a liquid mixture's sound speed and composition are directly correlated.…”

“…In the field of liquid sensing, a liquid mixture's sound speed and composition are directly correlated. By analysing the resonant frequencies of a PnC exposed to different liquid samples, researchers could precisely identify and quantify the components present, making it possible to monitor air quality, identify dangerous contaminants and even track greenhouse gas emissions with previously unheard-of precision 8,13 . Liquid sensing applications utilising PnC capitalise on the variations in the sound speed of binary liquid mixtures, making them ideal for detecting substances like propanol.…”