A Chinese scientist innovated a new technology of photoacoustic spectroscopy (PAS) in which a low cost polyvinylidene fluoride (PVDF) film was used as a cantilever to detect PAS signal.

The piezoelectric property of the PVDF made the PAS signal be "heard" directly without using interferometer to detect its vibration.

This work was made by LIU Kun, a research fellow of GAO Xiaoming’s group at Anhui Institute of Optics and Fine Mechanics (AIOFM), Hefei Institutes of Physical Science.

PAS offers several intrinsic attractive features including ultra-compact size, high sensitivity, wavelength-independent acoustic transducers and simple configuration.

Therefore, PAS is an ongoing research topic, of which lots of new scheme have been reported, such as cantilever enhanced photoacoustic spectroscopy (CEPAS), quartz tuning fork enhanced photoacoustic spectroscopy (QEPAS), multi-resonator photoacoustic spectroscopy and so on. Cantilever photoacoustic spectroscopy is one of the most sensitive techniques, but it requires optical interferometer to measure cantilever vibration which makes the structure complicated.

This newly innovated PVDF-PAS simplifes CEPAS configuration as it is free to use interferometer.

Feasibility of the introduced PVDF–PAS for gas sensing was demonstrated by measuring H₂O vapor.

As an alternative new technique for PAS, the use of PVDF film as PAS signal transducer offers good flexibility, water resistance, chemical stability, low cost, simple configuration and simple optical alignment which may have potential applications in sensing of oxydic or corrosive gases (such as O₃ and N₂O), as well as for applications under harsh or/and specific environmental conditions.

The work was supported by the National Natural Science Foundation of China (No. 41475023, No. 41575030) and Youth Innovation Promotion Association of Chinese Academy of Sciences (No. 2015263).

Link to the paper: A Novel Photoacoustic Spectroscopy Gas Sensor Using a Low Cost Polyvinylidene Fluoride Film

Figure 1 Schematic diagram of the developed PVDF-PAS experimental setup (image by LIU Kun)

Figure 2 PVDF-PAS signal of ambient H₂O vapor absorption (top) and linear response of PVDF-PAS signals to H₂O vapor concentrations (bottom) (image by LIU Kun)

Contact:

ZHOU Shu

Hefei Institutes of Physical Science (http://english.hf.cas.cn/)

Email: zhous@hfcas.ac.cn