The Auxetic prosthetic is a research project that explores the design field of prosthetics. Concepts covered include the upper body amputation support in detail, exploring design theories and methodologies in the field of amputated parts. This is highlighted through researching past, present and future of designed products and practitioners in the field of designing support for amputated limbs. The detailed report highlights concepts related to moulded, myoelectric, 3D printed prosthesis and bionic prosthesis. The report draws comparison between various type of 3D printing techniques to print auxetic structure. The results show a prototype of elbow down arm with auxetic prosthetic muscles. Overall achievement of the research is to successfully substitute actuator and gears from current upper body prosthesis by incorporating auxetic prosthetic muscle.
Each cell is designed to behave in auxetic way. FEA analysis was conducted to determine the stress and strains in each cell and complete system to find the total displacement. This displacement suggests the total length available to move each finger or hand. Stresses displayed total force that can be exerted through this auxetic muscle.
The complete auxetic muscle has extremely complicated geometry that creates very complex support structure. Different 3D printing methods were explored to determine which method is most suitable for the print job and can fulfil the design requirements of displacement and stress. We tried FDM, SLS and multi extruder FDM printing. To further explore possibilities of 3D printing auxetic structure we designed our own support structure, so we were not reliant on slicing software to generate the support. This allowed for time and material to be saved while making post printing work lean.