PVDF-based piezoelectric alarm system

Polyvinylidene fluoride (PVDF) receives an increasing amount of attention because of its strong piezoelectric response. PVDF is a highly non-reactive thermoplastic fluoropolymer with high piezoelectric voltage coefficient, wide frequency response, and excellent mechanical properties. A PVDF piezoelectric sensor is very sensitive to dynamic stress and suitable for detecting weak physiological signals. PVDF sensors with varying dimensions and electroding patterns, specific to an application are not easily available commercially. In this paper, the indigenously developed PVDF sensor has been appropriately designed as a sensing element to function as a security alarm for the first time. This sensor can be used at various critical locations of aircraft and for military and industrial areas against theft, damage as well as personal protection, where unwanted or untimely intrusions are to be arrested. The piezoelectric sensor responds immediately to any dynamic stimulus, which may be due to any unwanted episodes, and alerts the authorities. An electronic circuit is designed to support the sensing element, and the output is displayed in the form of glowing of light emission diode (LED) and an audio buzzer.