Miniaturized pultrusion and pullwinding

Micro profiles made of fiber reinforced plastics for MRI surgeries and diagnosis

Fiber reinforced plastics offer a valuable alternative to conventional materials for various medical applications: They can be used in magnetic resonance imaging (MRI) without any safety concerns, whereas metals interact with and disturb the magnetic field. At the same time, composites have the mechanical stability and flexibility required to replace instruments, prostheses and implants made of metal. Another advantage: Composite profiles are particularly lightweight and can be customized to perform specific functions. In miniaturized form, they offer enormous potential both for minimally invasive procedures and for post-op checkups without exposure to radiation.

Miniaturized pultrusion and pullwinding

At the Fraunhofer IPT, the micro-pultrusion and pullwinding processes were developed to produce miniaturized components made of fiber reinforced plastics. Our special purpose machines produce profiles with diameters below 500 µm and high fiber volume content. The fiber layers with continuously adjustable orientation are aligned in the micro-pullwinding process giving the profile its specific mechanical properties tailored to the requirements of the application. All commonly-used reinforcing fibers as well as thermosetting and thermoplastic materials can be processed. Customized semi-finished products, such as towpregs, can also be produced economically using the micro pultrusion process.

Our services

  • Development and setup of special-purpose machines for micro-pultrusion and micro-pullwinding processes to produce FRP micro-profiles in large scale
  • Providing support in terms of material selection, design, development and production planning
  • Material qualification of all fiber and matrix materials as well as semi-finished products
  • Providing support in the phase of medical certification of micro-pullwinding systems and products
  • Consulting services, technology and market studies

Application examples


CFRP clips for the treatment of aneurysms in the brain

Microimplants made of carbon fiber-reinforced plastics enable postoperative diagnosis in high-resolution, low-radiation MRI.

Multifunctional CFRP puncture needle

The Fraunhofer IPT has developed a multifunctional puncture needle made of fiber reinforced plastics. The CFRP needle is stiffer and stronger than metallic ones and enables completely artifact-free Magnetic Resonance Imaging (MRI). These needles were produced in a micro-pultrusion process. With an outside diameter of just 1 200 μm, the needle offers three lumen with 272 μm, 312 μm and 612 μm inside diameter, a cutting edge for the direct placement of the puncture needle to human tissue as well as a biocompatible surface coating. Two of the lumen permit minimally invasive operating instruments e.g. endoscope and laser to be used simultaneously, while the third provides a rinsing functionality. Standardized ports such as Luer-Lock adapters allow the puncture needles to be coupled with commercially available medical technology components.

GFRP guide wire

Guidewires are used in a range of minimally invasive surgeries such as stent positioning procedures. In order to utilize the outstanding imaging options for soft tissue provided by magnetic resonance imaging (MRI) in this type of intervention, it is essential to replace the metallic guidewires with guidewires made of alternative materials. The Fraunhofer IPT has developed the micro-pullwinding technology as part of the project “MIGI – Multifunctional Image Guided Interventions“, funded by the Federal State of North Rhine-Westphalia and by the EU. This has enabled MRI-conditional, fiber-reinforced plastic (FRP) guidewires with a flexible tip on an otherwise rigid shaft to be produced in one single process step.

Always well informed!

On request we will send you further information about our events and research topics. Please fill out our contact form.



Whether in aircraft, automobiles or bicycles, towpregs can be used in a wide range of applications requiring high material resistance combined with low weight.

Your advantages

Flexibility in production

Our modular systems can be flexibly adapted to the requirements of your prototype application. The choice of materials as well as their lay-up are perfectly matched to your requirements.

In-depth material

In our continuous processes we process thermosetting plastics such as epoxy resins and thermoplastics such as PEEK. The plastics are reinforced with all common fiber types such as carbon, glass or aramid and with special types such as basalt or glass capillaries.

Research know-how

Whether you are interested in puncture needles, guidewires or aneurysm clips – you can benefit from our decades of experience and our extensive expertise acquired in the course of application-oriented research projects on MRI-safe medical devices.