Additively manufactured temperature sensitive actuators made of shape memory wire reinforced polymer structures

• Applicants: Professor Dr.-Ing. Jürgen Fleischer; Professor Dr.-Ing. Kay Andre Weidenmann
• Subject Area: Plastics Engineering ; Synthesis and Properties of Functional Materials
• Term: from 2019 to 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 422469945

• Final Report Year: 2024

Final Report Abstract

The aim of the project was to additively manufacture a temperature-sensitive actuator based on a polymer structure functionalized with shape memory alloys. The first step was to select a material. After completing the mechanical and thermal characterization of the matrix materials in question, TPU was chosen. Based on the process framework conditions, a NiTi wire (equiatomic) was selected. In the second step, a device was developed to embed the selected wires manually and under tensile stress in the polymer matrix using the additive manufacturing process of Arburg Plastic Freeforming. The manufactured composite was mechanically characterized, with a particular focus on the interface properties. In addition, it was already possible to produce a simple actuator geometry with the device, which was characterized in the following, with a particular focus on quantifying the actuator function. At the same time, a model was created that depicted the actuator function and provided further information about the stress and temperature distribution in the composite. The production process was then extended in that the wire deposition was now automated and took place under tensile stress during the polymer printing process. The actuator samples produced in this process were then characterized again with regard to their function and the fatigue properties of the function. Finally, a reconstruction model of the samples was created using computer tomography and compared with the CAD model, which was transferred to the freeformer for production. In this way, it was possible to detect target/actual deviations in order to optimize the manufacturing process.

Publications

• Additive manufacturing of temperature sensitive actuators manufactured from NiTi shape memory wires embedded in polymer structures”. 23rd International Conference on Composite Structures, University of Porto, Portugal 2020
  Eyer, P., Trauth, A. & Weidenmann, K. A.
  
• “Material selection for temperature sensitive actuators manufactured from shape memory alloy wires embedded in polymer structures”. Proceedings 4th International Conference Hybrid Materials & Structures, p.288-295, Karlsruhe, Germany. 2020.
  Eyer, P., Trauth, A.,& Weidenmann, K. A.
  
• Improvement of the adhesion in functional NiTi wire/polymer composites made by additive manufacturing. Composite Structures, 275, 114455.
  Eyer, P.; Dittus, J.; Trauth, A.; Coutandin, S.; Fleischer, J. & Weidenmann, K.A.
  
• “Investigating the mechanical properties of polymer samples from different additive manufacturing processes using ultrasonic phase sprectroscopy”. 24 th International Conference on Composite Structures, University of Porto, Portugal, 2021
  Eyer, P., Trauth, A. & Weidenmann, K. A.
  
• "In-situ Widerstandsmessung additiv gefertigter Formgedächtnisaktoren“. 3. DGM Fachtagung Werkstoffe und Additive Fertigung, Dresden, 2022
  Eyer, P., Trauth, A. & Weidenmann, K. A.
  
• Influence of Stress on the Transition Behaviour of NiTi Shape Memory Alloys for Actuator Applications. International Conference on Shape Memory and Superelastic Technologies, 84291, 18-19. ASM International.
  Eyer, P.; Trauth, A. & Weidenmann, K. A.
  
• “Characterization of Shape-Memory-Wire/Polymer Composites from Additive Manufacturing. 25th International Conference on Composite Structures”, University of Porto, Portugal, 2022
  Eyer, P., Trauth, A. & Weidenmann, K. A.
  
• Aktorfunktion additive gefertigter NiTi/Polymer Verbunde. DGM-Fachausschusssitzung “Hybride Werkstoffe und Strukturen”, Kassel
  Eyer, P., Trauth, A. & Weidenmann, K. A.
  
• Aktorfunktion additive gefertigter NiTi/Polymer Verbunde. DGM-Fachausschusssitzung “Hybride Werkstoffe und Strukturen”, Kassel, 2023.P11 Eyer, P., Trauth, A., Weidenmann, K. A.: “Interface properties of shape memory-wire-polymer composites from additive manufacturing”. 26th International Conference on Composite Structures, University of Porto, Portugal, 2023
  Eyer, P., Trauth, A. & Weidenmann, K. A.
  
• Investigating the Mechanical Properties of Polymer Samples from Different Additive Manufacturing Processes Using Ultrasonic Phase Spectroscopy. 3D Printing and Additive Manufacturing, 11(2), e666-e674.
  Eyer, Philipp; Enzler, Sarah; Trauth, Anna & Weidenmann, Kay André