TY - JOUR
T1 - Additive manufacturing of non-assembly deployable mechanisms for the treatment of large bony defects
AU - Leeflang, M. A.
AU - Bobbert, F. S.L.
AU - Zadpoor, A. A.
PY - 2021
Y1 - 2021
N2 - Porous biomaterials are often used to treat large bony defects or fractured vertebras. Most of such biomaterials are made of metals and their alloys and have a pre-defined, fixed shape. Due to their predefined fixed shape, however, they are not suitable for implantation through minimally invasive surgical procedures. To overcome this problem, we designed three different deployable non-assembly mechanisms, which were manufactured using selective laser melting. These deployable geometries, including a bicapped cube, a bicapped trigonal antiprism, and a bicapped square antiprism, possess a large aspect ratio in their retracted state. Upon the application of an external force, they expand radially into their deployed load-bearing configuration. Using non-assembly manufacturing, revolute joints, wavelike elements, rigid rods and restrictions could be integrated into the design. The designs were manufactured in such a way that the least amount of support structures was required during the fabrication process. Additionally, the deployable structures were functional immediately after printing. Mechanical tests were performed to determine the forces required to deploy the designed structures and to determine their failure load. A maximum change of 322 ± 7% in the circumdiameter was found for the bicapped trigonal antiprism while the bicapped square antiprism showed the largest reduction in the height (61 ± 1%). A maximum force of 10.3 ± 1.6 N was required during the deployment process of the bicapped square antiprism 3. The bicapped antiprisms could support up to 1212 ± 45.5 N before they failed, while the bicapped cubes failed under a force of 232 ± 5.5 N. The elongated geometry of our designs makes them ideal for implantation using minimally invasive surgical procedures. Given the fact that these are the first non-assembly deployable bone substitutes manufactured using selective laser melting, further studies are required to make them suitable as orthopedic implants.
AB - Porous biomaterials are often used to treat large bony defects or fractured vertebras. Most of such biomaterials are made of metals and their alloys and have a pre-defined, fixed shape. Due to their predefined fixed shape, however, they are not suitable for implantation through minimally invasive surgical procedures. To overcome this problem, we designed three different deployable non-assembly mechanisms, which were manufactured using selective laser melting. These deployable geometries, including a bicapped cube, a bicapped trigonal antiprism, and a bicapped square antiprism, possess a large aspect ratio in their retracted state. Upon the application of an external force, they expand radially into their deployed load-bearing configuration. Using non-assembly manufacturing, revolute joints, wavelike elements, rigid rods and restrictions could be integrated into the design. The designs were manufactured in such a way that the least amount of support structures was required during the fabrication process. Additionally, the deployable structures were functional immediately after printing. Mechanical tests were performed to determine the forces required to deploy the designed structures and to determine their failure load. A maximum change of 322 ± 7% in the circumdiameter was found for the bicapped trigonal antiprism while the bicapped square antiprism showed the largest reduction in the height (61 ± 1%). A maximum force of 10.3 ± 1.6 N was required during the deployment process of the bicapped square antiprism 3. The bicapped antiprisms could support up to 1212 ± 45.5 N before they failed, while the bicapped cubes failed under a force of 232 ± 5.5 N. The elongated geometry of our designs makes them ideal for implantation using minimally invasive surgical procedures. Given the fact that these are the first non-assembly deployable bone substitutes manufactured using selective laser melting, further studies are required to make them suitable as orthopedic implants.
KW - Bone regeneration
KW - Deployable structures
KW - Non-assembly mechanisms
KW - Selective laser melting
UR - http://www.scopus.com/inward/record.url?scp=85111287705&partnerID=8YFLogxK
U2 - 10.1016/j.addma.2021.102194
DO - 10.1016/j.addma.2021.102194
M3 - Article
AN - SCOPUS:85111287705
SN - 2214-8604
VL - 46
JO - Additive Manufacturing
JF - Additive Manufacturing
M1 - 102194
ER -