Piezoceramic fibers and composites

At Fraunhofer IKTS, piezoceramic fibers are developed and manufactured using a wet-spinning process. This provides a high-performance technology for producing dense piezoceramic fibers based on lead-containing (PZT) and lead-free (KNN) materials. The fibers can be produced as standard with diameters ranging from 100 µm to 800 µm and a length of 150 mm.

Embedding the piezoceramic fibers in polymer materials creates piezoelectric composites that combine the advantages of piezoceramics (high electromechanical coupling) with those of the matrix material (low acoustic impedance, flexibility). Depending on the specific application, piezoelectric transducers for ultrasonic technology or structural monitoring can be manufactured through the targeted selection and arrangement of components, 3D machining, and structured electrode deposition. Depending on customer requirements, 1-3-piezo composites with regular or irregular fiber arrangements and a filling ratio of 20 to 80 vol.% can be produced. Due to their adjustable resonance frequency (40 kHz–8 MHz) across the transducer thickness, these materials are particularly well-suited for ultrasonic transducers used in sonar and medical technology, as well as for non-destructive material testing.

Services offered

• Development and production of ceramic fibers (d = 100–800 µm) using wet spinning processes
• Development and fabrication of 1-3-piezo composites for ultrasonic transducers in the 40 kHz–8 MHz frequency range with regular or irregular fiber arrangements
• Design and fabrication of piezo-composite transducers for medical technology, sonar technology, non-destructive material testing, or structural health monitoring  
• Characterization of dielectric, electromechanical, and acoustic properties

Technical equipment

• Fiber production: planetary ball mill, agitator ball mill, centrifugal mixer, dissolver, rolling mill, fiber spinning line
• Composite production: polymer infiltration, CNC milling machine, grinding and polishing technology, sputtering system, screen printer with automatic positioning
• Characterization: Rheometer, microscopes, small-signal measurement (permittivity, dielectric loss factor, coupling factor), large-signal measurement (ferroelectric hysteresis, stress-strain behavior, blocking force), pulse-echo measurement, sound field measurement, vibration behavior (laser vibrometer)