Influence of Fabric Electrode on Polyvinylidene Fluoride Piezoelectric Film Property.

Influence of fabric electrode on polyvinylidene fluoride (PVDF) piezoelectric film property was studied. Sheet resistance of 3. 5 Ω·cm² silver paste screen printing polyester fabric was prepared by screen printing method. Silver-plated polyester fabric and copper screen fabric with same sheet resistance were selected. Three kinds of fabric were used as electrode together with PVDF piezoelectric film to encapsulate and prepare flexible piezoelectric sensor. Dielectric contact property, sensitivity and durability of the three fabric piezoelectric sensors were tested. The test results showed electrode dielectric impedance of silver-plated fabric and copper screen fabric were stable when the frequency was lower than 4 kHz. When the frequency was around 1x10⁴ Hz, the fluctuation of relative dielectric constant for silver paste screen printing fabric electrode was obvious. It was obviously higher than those of the other two fabric electrodes under high frequency condition. The dielectric property of silver-plated fabric electrode was close to that of copper screen fabric electrode. The three kinds of electrode all had a certain piezoelectric susceptibility. The sensitivities of silver paste screen printing fabric electrode and copper screen fabric electrode were slightly higher. After 2 000 times of pressing, sawtooth square signals still could be output for silver-plated fabric electrode and copper screen fabric electrode. Obvious baseline drift phenomenon was appeared for silver paste screen printing fabric electrode. It is considered that the overall properties of flexible piezoelectric sensor packaged by copper screen fabric as electrode are better. Dielectric property and durability of silver-plated fabric are better. Sensitivity of silver paste screen printing fabric is better. The three kinds of fabric can be used as electrode material to produce sensor. However, problems like motion artifact and so on need to be further studied. [ABSTRACT FROM AUTHOR]