Flexible over-moded resonators based on P(VDF-TrFE) thin films with very high temperature coefficient

Area of Science:

• Materials Science
• Sensor Technology
• Polymer Electronics

Background:

• Flexible electronic devices require novel sensing materials and structures.
• Over-moded resonators (OMR) offer unique electromechanical properties.
• Poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) is a piezoelectric copolymer with potential for sensor applications.

Purpose of the Study:

• To develop and characterize a flexible over-moded resonator (OMR) based on P(VDF-TrFE) thin films for temperature sensing.
• To evaluate the performance parameters of the OMR, including its temperature coefficient of frequency (TCF).
• To explore the potential of these devices as low-cost, high-precision temperature sensors.

Main Methods:

• Fabrication of flexible OMRs on elastic substrates using inkjet-printed electrodes.
• Polarization of P(VDF-TrFE) sensing films via the corona method.
• Characterization of OMR performance, including frequency variation with temperature and electromechanical coupling coefficient.

Main Results:

• The P(VDF-TrFE) based OMRs demonstrated a linear frequency response to temperature changes.
• A very high temperature coefficient of frequency (TCF ≫ 1600 ppm/°C) was observed.
• The electromechanical coupling coefficient and quality factor were characterized across a range of temperatures.

Conclusions:

• Flexible OMRs utilizing P(VDF-TrFE) thin films are suitable for temperature sensing applications.
• The high TCF and linear response indicate suitability for low-cost, high-precision temperature sensors.
• Further characterization of electromechanical properties at different temperatures provides insights into device behavior.