Ultrasonic Sensors and Processes

Group

The »Ultrasonic sensors and processes« workgroup of Fraunhofer IKTS at the Dresden Klotzsche site is in charge of methodical planning and simulation-based optimization of ultrasonic-based test methods as well as their implementation in devices and equipment. All this is done primarily based on the institute’s own PCUS® pro-Plattform. The devices and software of the PCUS® pro family are developed by the workgroups »Electronics for testing systems« and »Software for testing systems«. If required, highly sensitive and reliable ultrasonic probes and sensors for special applications complete the platform. These are designed and manufactured in the institute’s own lab.

Design and optimization

© Fraunhofer IKTS
Ultrasonic wave propagation in a transmission/reception probe, calculated with software developed at Fraunhofer IKTS.

The complexity of novel materials and components means that simulation-based planning and optimization of probes and the continuous adaptation of test methods are gaining in importance. The complete test sequence including sensors can be simulated beforehand on the computer. The purpose is to test the set-up for physical plausibility and sensitivity and make the manufacturing process more economically efficient.

When development times are short, modeling and simulation help avoid bad planning and enable a systematical optimization of test parameters. With this aim in mind, the »Ultrasonic sensors and processes« workgroup has for many years been developing its own high-performing computing programs and imaging analysis algorithms. These are available in a module library. They can be extended in an efficient way and quickly adapted to suit new test requirements and tasks.

Development of specialized probes

Where commercially available probes are not suited for specific applications, the sensor lab of IKTS is able to design and manufacture ultrasonic transducers. High-performance simulation tools and equipment such as a waver saw, d33 meter (piezometer) and HF pulser-receivers up to 500 MHz are available for this purpose. 

Some examples for specialized applications are high-temperature sensors, high-frequency aluminum nitride thin-film oscillators, curved piezocomposite probes as well as highly sensitive transducers based on piezoelectric monocrystals, such as lead magnesium niobate/lead titanate (PMN-PT). The available transducer types are single-element transducers, phased-array sensors, acoustic emission sensors and transmit/receive probes. They can be adapted for special component geometries and integrated in test tongs.

© Fraunhofer IKTS
Ultrasonic phased-array probe, optimized and manufactured by IKTS, for applications at curved components.
© Fraunhofer IKTS
Specially designed test tongs with three integrated phased-array probes for testing folds in automotive applications.
© Fraunhofer IKTS
Imaging-based visualization of an ultrasonic test of spot-welded joints (bottom row, in color), determined with a mobile TFM phased-array system developed at IKTS (TFM: total focusing method). Compared with this: the results at the same welded spots as obtained from stationary ultrasonic microscopy as reference (top row, in grayscale).

System development

The »Ultrasonic sensors and processes« workgroup realizes and coordinates the full integration of methods and algorithms in client-specific hardware and software. The group is also in charge of converting test methods into equipment, down to the construction of industrial prototypes in Germany and abroad.

The group currently focuses on developing special high-resolution scanners and robot-based testing systems for free-form components with complex shapes and of various material classes.

© Fraunhofer IKTS
Dual-robot machine for testing complex 3D free-form components, based on IKTS’ own PCUS® pro hardware and software platform, with squirter coupling
© Fraunhofer IKTS
Detail of the dual-robot machine for testing complex 3D free-form components with squirter coupling.

Service portfolio

 

  • Basic research and feasibility studies
  • Development of methods and simulation-based optimization
  • Development of (imaging) analysis algorithms and application-specific simulation tools
  • Development and manufacture of ultrasonic transducers for special applications
  • Manufacture of application-specific sensor materials (1-3 composites) based on PZT and PMN-PT
  • Manufacture of client-specific acoustic stacks
  • Characterization of piezoactive materials using d33 meter (piezometer)
  • Electric and acoustic characterization of ultrasonic probes
  • Development and design of high-resolution ultrasonic scanners
  • Realization of complex automated robotic test facilities
  • Inline and offline test solutions based on our proprietary PCUS® pro platform
  • Licensing models for industry clients
  • R&D cooperation with companies and research institutions

 

Range of equipment

 

  • Scanning acoustic microscope (SAM) for frequencies up to 400 MHz
  • High-resolution scanner for ultrasonic and laser ultrasonic applications up to 100 MHz (self-built)
  • Ultrasonic goniometer for surface characterization (self-built)
  • Laser Doppler vibrometer for measuring sonic fields
  • Wafer saw
  • High-precision face grinding machine
  • d33 meter (piezo testing)
  • PCUS® pro ultrasonic hardware platform (single, multi, phased-array, HF)
  • HF pulser-receiver, up to 500 MHz
  • Air ultrasonic test facility (self-built)
  • Measuring station for controlled charging and discharging of rechargeable battery cells and for acoustic measurement of battery cells and extrudates
  • Ultrasonic spectroscopic measuring station for frequency-dependent characterization of liquids and solid bodies
  • Temperature-controllable water bath up to 60 °C, with scanning device

 

Industrial solutions

 

Current research

Ultrasound test system of tension-proof crimp connectors on catenaries

Current research

Monitoring of laser narrow-gap weldings of thick-walled components

Topic

Piezocomposite transducers

Topic

Manufacture of PMN/PT probes

Topic

Ultrasonic phased-array test tongs

Topic

Ultrasonic spectroscopy