Fluoroethylenepropylene ferroelectret films with cross-tunnel structure for piezoelectric transducers and micro energy harvesters
- School of Physics Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China)
Layered fluoroethylenepropylene (FEP) ferroelectret films with cross-tunnel structure were fabricated from sheets of FEP films by template-patterning followed by a fusion-bonding process and contact charging. The typical piezoelectric d{sub 33} coefficients, measured by a quasi-static method of samples not annealed, are in the range of 1000–3700 pC/N. The resonance behavior of the samples is analyzed by dielectric spectroscopy which also yields Young's modulus. Microphones built with such films exhibit a somewhat decreasing frequency response up to 1 kHz, an increase of the responses due to diffraction effects at higher frequencies, and eventually a peak probably due to a thickness resonance at about 40 kHz. Annealing at 125 °C indicates that the sensitivity stabilizes at about 40% of the original value. From this data, stable dynamic d{sub 33} coefficients of up to 300 pC/N can be calculated. A micro energy harvesting generator utilizing these films and based on the excitation of thickness vibrations is also described. With an active area of 4.3 cm{sup 2} and a seismic mass of 69.5 g, power up to 0.5 μW referred to an acceleration of 1 g can be generated at a frequency of 120 Hz.
- OSTI ID:
- 22314305
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 7 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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