Comparison of PEEK and UHMWPE Cranial Implants Fabricated at Room Temperature Using Single Point Incremental Forming (SPIF)

Abstract:

The human skull can become fractured or injured through impact and often requires repair through a craniectomy and subsequent cranioplasty, surgery performed to repair defects or damage to the cranium. Challenges related to material choice, which must be biocompatible, and customization for each patient’s anatomy remain. One possible solution is fabrication of patient-specific cranial implants, out of biocompatible polymers, using single point incremental forming (SPIF). In this paper, polyetheretherketone (PEEK) and ultra-high molecular weight polyethylene (UHMWPE) are formed using SPIF at room temperature to manufacture a cranial implant. The SPIF process is used to produce formed parts from which test specimens were extracted to evaluate the tensile performance and thermal properties. Formed cranial implants were impacted using a drop weight to evaluate their suitability under relevant conditions. The geometric conformance of the SPIF process was studied to compare the material behavior for the specified polymers after forming. The results validate that SPIF can be conducted at room temperature with PEEK and UHMWPE biocompatible polymers to enable custom implant manufacturing. However, PEEK exhibited superior performance in terms of tensile strength, geometric conformance, energy absorption, and melting temperature, and is recommended over UHMWPE for future implant applications.

• Periodical: Solid State Phenomena (Volume 389)
• Pages: 37-49
• DOI: https://doi.org/10.4028/p-CeZQ53
• Online since: April 2026
• Authors: Elizabeth Mamros, Austin Clark, Philip Barnett, Ihab Ragai*, Shaffer Derek, Kristofer Laser Jr
• Keywords: Biocompatible, Cranioplasty, Impact Testing, Implants, Incremental Forming, PEEK, UHMWPE

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