PVDF sensor

Experiments were conducted to calibrate the PVDF sensor. To avoid the influence from the actuation voltage, we simply tapped the composite beam tip and measured simultaneously the charge amplifier output and the tip displacement. The displacement was measured with a laser distance sensor (OADM 20I6441/S14F, Baumer Electric, Southington, CT). Fig. 8.3(a) shows the measured charge response under the damped beam oscillation at 42 Hz, while Fig. 8.3(b) depicts the measured charge vs. the actual displacement, from which we can conclude that the beam tip displacement can be well captured by the PVDF sensor. 

Fig. 8.3 Experimental validation of the PVDF sensor and the charge amplifier circuit ...

A model-based compensation scheme can be used to greatly reduce the impact of feedthrough coupling on the accuracy of PVDF sensor output. 

Fig. 8.11 The performance of the integrated PVDF sensor with model-based compensation. Reprinted from [Chen et al. (2007a)j.

Although piezoelectric properties such as relative permittivity and piezoelectric coefficients change with the temperature, the total effect for the calibration of PZT sensors far below the Curie temperature is very small. However, PVDF foils show a significant temperature dependence of the pyroelectric properties in addition to their temperature depending piezoelectric features. Thus PVDF sensors are quite temperature sensitive, and in general, an appropriate temperature compensation is necessary. This behaviour, however, can be improved by special forming and spatial distribution of the PVDF sensors [100]. 

Studies of pressure fields generated by commercial lithotripsy devices [49-56] have demonstrated the benefits of PVDF sensors in terms of measured pulse fidelity over conventional quartz or tourmaline ballistics pressure transducers. These latter transducers, while robust, have resonant frequencies less than 1 MHz and element dimensions of several millimeters [57, 58]. 

Imaizumi S, Ohtsuki Y, Yasuda Tet al (2013) Printable polymer aetuators from ionic liquid, soluble polyimide, and ubiquitous carbon materials. ACS Appl Mater Inter 5(13) 6307-6315 Jeon JH, Kang SP, Oh IK (2009) Novel biomimetie actuator based on SPEEK and PVDF. Sensor Actuators B 143(l) 357-364... 

A computerized system using a platform with 128 PVDF sensors has been designed as a tool for posture rehabililation [24]. The purpose of this system is to allow for improved understandng of the mechanisms involv in foot load transfer for diagnosing and programming corrective rehabilitative procedures. 

B. Andre. J. Oot, E. Partouchc. snd J. J. Simonnc, Thin film PVDF sensors applied to high acceleratioa measurements. Sensors and Actuaton A 33 111-114 (1992). 

In spile of the case of construction, robustness, and high sensitivity, the lack of a truly static response of a ferroelectric polymer pressure transducer represents a serious limitation to widespread use of this type of device. Several techniques can be conceived in order to overcome this drawback [21] (such as the parallel use of a strain gauge sensor and the use of this transducer to calibrate at intervals the signal detected by the PVDF sensor), but excessive complexity and costs are usually added to the originally simple and cheap design of the piezoelectric polymer catheter-tip sensor. 

Artist front view definition of the PVDF sensors. 

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