Compósitos baseados em PLA e ABS para impressão 3D de simuladores antropomórficos

Abstract

Additive manufacturing has been standing out for some years in both scientific and industrial fields. One of the 3D printing methods by material extrusion that stands out is the fused filament fabrication technique (FFF). This method uses raw materials in the form of filaments and for this reason, much research is focused on obtaining suitable filaments for specific applications. In the health area, personalization is relevant due to the specificity of each human being. One example is the development of anthropomorphic simulators (personalized medical devices based on computed tomography (CT) scans that aim to ensure a faithful 3D model representation of a patient. The applications of these devices involve therapies and laboratory tests where exposure to radiation occurs and, due to this, there is a need for them to reproduce the intensity and similarity of human tissues (soft and bone) when exposed to X-rays. In this work, compounds of polymeric materials with ceramics were developed and the attenuation of each mixture was determined, in the Hounsfield Unit (HU) scale, used in computed tomography exams. ABS and PLA polymers were combined with various ceramic fillers (hydroxyapatite, aluminum oxide, zirconium oxide and bismuth carbonate). For mimick of bone tissue, the ABS sample with zirconium oxide or bismuth carbonate experienced results above the minimum limit of cortical bone tissue, of 225 Hounsfield Unit (HU), reaching values close to 2000 HU with 12% of bismuth carbonate. For soft tissues, hydroxyapatite and aluminum oxide did not show considerable improvements over pure polymers due to the porosity of the printed samples. To adapt the rheology of the filaments to the printing process, stearic acid and carnauba wax were used as surfactants. The two additives proved to be adequate to improve the distribution of the particles in the polymers, and maintained the fluidity of the mixtures close to those of the pure polymers. The 3D printing tests of a head and neck simulator, using a double-head printer, with one of the nozzles imitating soft tissue and the other imitating bone tissue, demonstrated satisfactory results in imaging with panoramic radiography, cone beam computed tomography (dental), and computed tomography (medical). [resumo fornecido pelo autor]