Effect of HEC/PVDF coating on glass substrate for formaldehyde concentration sensing

This paper has reported demonstration of simple and low cost formaldehyde sensor utilizing Hydroxyethyl cellulose/Polyvinylidene fluoride (HEC/PVDF) coated glass substrate. It was integrated with Arduino microcontroller for data acquisition of the variation of the transmitted light during the sensing. The formaldehyde detection is based on the change in refractive index (RI) of the HEC/PVDF as a sensitive material which modulate the output light intensity when the concentration level of the formaldehyde increases. A significant response towards formaldehyde concentrations level was observed with the output voltage reduced linearly from 1.5V to 0.8V. The sensitivity of the proposed sensor improves by a factor of 1.09 as compared to uncoated glass substrate. It also performed better in term of stability, response time and hysteresis. The proposed sensor evades the used of costly optical sensor fabrication and manufacturing process which are more practical for large production while maintaining a good sensing performances. Based on the experiment results, the proposed approach has exhibited convincing potential as a formaldehyde sensor.