3D Printed Gyroid Designs for Pressure Sensing Applications

The use of gyroid structures in pressure sensing applications presents a unique combination of strength and energy absorption, making them ideal candidates for 3D printing. Their self-supporting design facilitates effective layering in the fused deposition modeling (FDM) process.
This presentation summarizes energy absorption capabilities within a triply periodic minimal surface (TPMS) gyroid model, showcasing a novel design that incorporates thin gyroid structures with double hollow struts, thus enhancing energy absorption efficiency.

Also, we present the development of a G slab-based capacitive pressure sensor created using advanced robotic 3D printing technology, which achieves an impressive pressure sensitivity of 78.43 MPa^-1 within the 0 to 0.060 MPa range and maintains a sensitivity of 13.72 MPa^-1 at operational pressures up to 0.181 MPa. The culmination of this research is the design of a smart helmet capable of detecting critical pressure changes, representing a significant advancement in protective headgear technology.

To comprehensively explore the energy absorption potential of the gyroid microstructure, we designed a series of TPMS structures with diverse strut configurations and thicknesses. Our work revealed that the presence of struts enhances stiffness, with the G slab model demonstrating superior energy absorption capabilities. Additionally, introducing hollow structures into the struts showed promise in boosting energy absorption while maintaining structural rigidity, with these effects modulated by the strut wall thickness.

In practical applications, we crafted a G slab-based sensor utilizing a hybrid FDM and robotic printing process, which involved the precise extrusion of conductive ink onto a hyper-elastic substrate. Our examinations of the sensor's sensitivity revealed a capacitance change of 78.43 MPa^-1 across varying pressure ranges, alongside mild hysteresis in lower displacement values due to bending effects, which increased linearity at higher displacements. Ultimately, we leveraged the G slab's energy absorption capabilities to enhance helmet design. The TPMS G slab liner was reinforced based on simulated force distribution, optimizing its thickness and volume fraction to maximize performance. This energy-absorbing layer is supported by a rigid outer shell, providing enhanced protection. Furthermore, integrating the G slab-based capacitive sensor into the helmet introduces deformation sensitivity while preserving the energy-absorbing features characteristic of high-performance bicycle helmet liners. Future developments will aim to extend these applications across various sports, including National Football League (NFL) helmets, and will explore further enhancements such as increased pressure ranges and accelerometer integration.