Tailoring elastomeric meshes with desired 1D tensile behavior using an inverse design algorithm and material extrusion printing

Abstract

Additive Manufacturing (AM) is a highly attractive technology in the production of medical devices due to its capability to tailor product functionalities in line with a person's complex body structure. AM can resolve the chronic discomfort of body-supporting devices felt by people, especially those that suffer from imprecise fits, inconvenience with adjustments required in these devices to fit the body, or limitation of body movements to normal operating ranges. To enhance the user experience of those who wear medical devices, elastomeric meshes with programmed “waves” can be additively produced to enable an adjustment of the tensile stiffness in small-strain and large-strain sections. In this study, we demonstrate a method by which to adjust the stiffness transition point from low small-strain stiffness to high large-strain stiffness of additively manufactured sinusoidal and semicircular elastic fibers and determine the key design factors for transition points. Mechanics model predicts the 1D tensile behavior and experiments with controlled mechanical testing verify the model. We reveal the major design factors that can induce the difference in the stiffness akin to on-off before and after transition. In addition, we produce meshes by the superposition of different wavy fibers, leading to multi-transition tensile behavior and thus expanding the area where mechanical properties can be controlled. An inverse design strategy is developed to improve the utility of an elastomeric mesh which enables the facile customization of the mesh with desired properties. Finally, we demonstrate that users can implement desired functions - not only the size but also the degree of body restriction - through proper settings by producing locally tailored wearable mesh-aid devices. © 2022 Elsevier B.V.