Design and characterization of a PVDF ultrasonic range sensor

Area of Science:

• Robotics
• Materials Science
• Sensor Technology

Background:

• Development of advanced sensors is crucial for robotic systems.
• In-air ultrasonic sensors require precise fabrication and material properties.

Purpose of the Study:

• To fabricate an ultrasonic sensor for in-air applications using ferroelectric polymer technology.
• To evaluate the performance of the sensor for robotic gripper integration.

Main Methods:

• Fabrication of unimodal transducers from polyvinylidene fluoride (PVDF) polymer.
• Utilizing a strip of 40-mum-thick PVDF, curved to form transmitter and receiver elements.
• Characterization of transducer properties including resonance frequency and quality factor.

Main Results:

• The ultrasonic sensor achieved a maximum detectable distance of 300 mm with an axial resolution of 3 mm.
• Transducers with a resonance frequency of 380 kHz demonstrated a 100 mm maximum distance and 2 mm resolution.
• Key performance metrics like resonance frequency (63.5 kHz), quality factor (Q ≈ 12), and piezoelectric coupling (k(31) = 0.29) were determined.

Conclusions:

• Ferroelectric polymer technology is suitable for fabricating effective in-air ultrasonic proximity sensors.
• The developed sensor meets requirements for integration into multiple sensing robotic grippers.
• The technique allows for tunable sensor performance by adjusting transducer characteristics.