Under Pressure - Voxel Materiality of 3D Printed Auxetics

3D printing offers new opportunities in the design and manufacture of auxetic materials, which behave the opposite to conventional materials by expanding under tension and contracting under compression. Through this, auxetics demonstrate unique properties like enhanced indentation resistance, energy absorption, vibration resistance, and shape conformability.

While 3D printing acts as an enabling technology for the manufacture of auxetics and their complex microstructures, single material mechanisms are limited by their design, compromising the auxetic performance. Through multi material 3D printing, the simultaneous deposition of rigid and flexible material is possible. This makes a cellular design that utilises flexible material in the hinge area and rigid material for struts possible. The resulting multi material auxetic not only avoids buckling problems but offers new possibilities in tailorability by increasing the ability to control the mechanical behaviours of the designed material.

This work explores volumetric material 3D modelling at voxel level, enabling control of material choice at droplet level through material jetting 3D printing. This microscale control of multi materiality increases the design freedoms and enables digitally tailored material gradients, which relate to controllable and gradual changes in material performance.

By refining material design to the smallest definable unit, and utilising the print resolution of the Stratasys J850 3D printer, this research harnesses the control gained through the capabilities of volumetric material design. A procedural workflow is developed and used to enhance auxetic materials for customised sporting products. A bicycle saddle and handlebar grips with auxetic properties are developed, sporting personalised stiffness zones achieved through pressure mapping and a procedural modelling design process.