Piezoelectric PVDF cables

The authors report the development of a manufacturing technology leading to a simple and efficient method of endowing PVDF polymer with oriented structure by means of drawing dies. The thermal conditions of orientation processing have been optimized to obtain a high beta phase content. The technology of applying the outer piezoelectric-cable electrode by the hot method simplifies the process of manufacturing the piezoelectric cable considerably. Thanks to its structure the cable can operate in difficult environmental conditions, e.g. under water or under a layer of soil. The sensor is extremely resistant to chemical attack and to mechanical impact. Another equally important advantage of the sensor is its very wide transmission band which for the acoustic wave extends up to a frequency of about 1 GHz. The linear form of the sensor makes it suitable for monitoring large industrial, military and other facilities. The sensor´s considerable flexibility enables its shape to be changed and fitted to the shape of an area to be protected.