1 Introduction
2 Mass personalisation of orthoses
- Vat photo-polymerisation: an additive manufacturing method in which a liquid polymer contained in a vat is selectively cured using UV radiation from a laser or a lamp.
- Material jetting: an additive manufacturing process in which droplets of build material are selectively deposited through a nozzle.
- Material extrusion: an additive manufacturing process in which melted material is selectively dispensed through a nozzle.
- Powder bed fusion: an additive manufacturing in which thermal energy (laser or electron beam) selectively fuses regions of a powder bed.
- Binder jetting: an additive manufacturing process in which a liquid binder is selectively deposited to join powder materials.
- Sheet lamination: an additive manufacturing process in which sheets of materials are bonded to form a 3D component.
- Direct energy deposition: an additive manufacturing process in which thermal energy is used to fuse materials by melting them as the material is being deposited.
3 3D-printed orthoses
3.1 Vat photo-polymerisation
3.2 Material extrusion
3.3 Powder bed fusion
4 Challenges and conclusions
- Most additive manufacturing machines have a working volume smaller than the dimensions of the exoskeleton. In this case, different components must be considered, printed and finally assembled. This increases labour time and cost.
- Additive manufacturing has been used to produce small-scale passive orthoses or components for large-scale passive orthoses. The use of additive manufacturing for the fabrication of active exoskeletons is an important challenge requiring not only in printing the built material but also to embed sensors and actuators during the fabrication process.
- Additive manufacturing allows freedom of design. In the case of the design of orthoses, this means that new functionality can be considered. The combination of the shape or topology optimisation tool with additive manufacturing, for example, allows the fabrication of lightweight structure without compromising the mechanical performance. Therefore, the design of orthoses to be produced through additive manufacturing must also take into consideration the characteristics and constraints of each technique (design for additive manufacturing).