Spray deposition of piezoelectric polymer on plastic substrate for vibrational harvesting and force sensing applications

Abstract

Piezoelectric structures on flexible substrates are fabricated by using spray deposition of polyvinylidene fluoride (PVDF) film on conductive polymer, serving as electrode. The spray deposition conditions are optimized in term of uniform film with high piezoelectric phase content. It was found that the best piezoelectric dynamic and static response is obtained at solution with PVDF concentration 10 wt% sprayed at 70 ℃. The average roughness of the films is 12 nm and the β-phase with piezoelectric properties is 72%. The maximum generated voltage in energy harvesting (dynamic) mode is 300 mV at 3.4 g vibrations load with frequency of 50 Hz. In force detection (static) mode the structures exhibit high sensitivity of 225 mV/g and satisfying linearity of 95.3%. Due to the elastic polymer/polymer interface the structures demonstrate great durability after 6000 cycles of intensive vibrations with maximum degradation of the electrical parameters of 17%.

Keywords

• vibrational harvesting| piezoelectric polymer| plastic substrate| force sensing| spray deposition| PVDF| PEDOT:PSS