Article
Thermodynamics
Guangpeng Feng, Lin Qiu, Yanhui Feng, Xinxin Zhang
Summary: A topology optimization framework based on isotropic material is developed to design highly thermal conductive porous structures. The study shows that by optimizing the microstructure, it is possible to achieve thermal conductivity and mass diffusivity close to theoretical bounds. The selective laser melting technique enables the accurate fabrication of the microstructure of these lattice materials.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Materials Science, Multidisciplinary
Rossana R. Fernandes, Ali Y. Tamijani
Summary: This paper presents an experimentally validated framework for performing topology and orientation optimization of lattice structures subject to stress constraints. Effective stiffnesses and yield stresses of a unit cell are obtained using numerical homogenization and implemented via macrostructure topology optimization to improve lattice structure stiffness.
MATERIALS & DESIGN
(2021)
Article
Chemistry, Multidisciplinary
Ioannis Ntintakis, Georgios E. Stavroulakis
Summary: Additive Manufacturing (AM) is an advanced method for manufacturing high-strength and lightweight microstructures. Topology Optimization (TO) can create high-strength and mass optimized microstructure lattices. Experimental studies show that the mapping angle of the lattice structure significantly affects its mechanical behavior.
APPLIED SCIENCES-BASEL
(2022)
Article
Computer Science, Interdisciplinary Applications
Bin Li, Xiaoying Zhuang, Xiaolong Fu, Timon Rabczuk
Summary: This paper presents a new methodology for topology optimization of microstructures based on perturbation analysis and the penalty methods. The homogenized material coefficients are computed numerically using perturbation analysis, and periodic boundary conditions are imposed using the penalty methods. Sensitivity analysis is implemented without the need for the adjoint method, and the method can also be extended to multi-field analysis.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Computer Science, Interdisciplinary Applications
Masayoshi Matsui, Hiroya Hoshiba, Hiroki Kamada, Hiroki Ogura, Junji Kato
Summary: Advances in 3D-printing technology enable the manufacture of structures with lattice structures, providing superior mechanical performance compared to uniform solids. However, existing approaches often fail to consider connectivity between microstructures, resulting in unrealistic discontinuous structures and poor mechanical performance. This paper proposes a method to introduce an enlarged connective domain to improve connectivity and mechanical performance. The method combines unit cells of adjacent microstructures to form the microstructure of the connective domain, allowing micro-scale connectivity to be reflected in the macrostructure. Optimization analyses for two- and three-dimensional problems demonstrate the effectiveness of the proposed method.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Engineering, Manufacturing
Jaewook Lee, Chiyoung Kwon, Jeonghoon Yoo, Seungjae Min, Tsuyoshi Nomura, Ercan M. Dede
Summary: This paper introduces a systematic design procedure for shell-infill structures in additive manufacturing, utilizing multiscale topology optimization and a de-homogenization scheme compatible with Computer-Aided Design (CAD). The effectiveness of the design procedure is demonstrated through validation with design examples and fabrication using a multi-jet printing machine.
ADDITIVE MANUFACTURING
(2021)
Article
Mechanics
Kyeong-Soo Yun
Summary: This paper proposes a multi-material topology optimization method for designing microstructures of porous viscoelastic composites with prescribed relaxation moduli. The effective relaxation moduli of the composites are obtained through the homogenization method. The study applies density-based topology optimization and introduces a material interpolation scheme to determine an optimal material distribution with the prescribed modulus in both the glassy and rubbery regions. The proposed method is demonstrated effective through numerical examples and compared with theoretical bounds on the relaxation moduli of the optimized microstructures.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Computer Science, Interdisciplinary Applications
Naruethep Sukulthanasorn, Hiroya Hoshiba, Koji Nishiguchi, Mao Kurumatani, Robert Fleischhauer, Kuniharu Ushijima, Michael Kaliske, Kenjiro Terada, Junji Kato
Summary: This paper presents a two-scale topology optimization framework for determining the optimal microstructure in porous material under transient heat conduction and transfer. The proposed optimization model can consider the surface area directly from microstructure topology to enhance heat transfer performance.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Computer Science, Interdisciplinary Applications
L. M. Anaya-Jaimes, W. M. Vicente, R. Pavanello
Summary: This work presents a Bi-directional Evolutionary Structural Optimization (BESO) based methodology for designing orthotropic metamaterials with a specific thermal expansion coefficient. The proposed method stabilizes the evolutionary process using material interpolation and numerical strategies and uses the homogenization method to obtain the equivalent thermal expansion properties of the designed materials.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2022)
Article
Materials Science, Multidisciplinary
Heng Zhang, Akihiro Takezawa, Xiaohong Ding, Shipeng Xu, Pengyun Duan, Hao Li, Honghu Guo
Summary: This study introduces a novel topological optimization technique for designing biodegradable composites with controlled stiffness. Maximizing material stiffness while considering material degradation over time was the main objective. Sensitivity analysis was conducted to deduce the impact of design variables on the objective. The proposed method was shown to be effective in several design examples with different degradable interface boundary conditions.
MATERIALS & DESIGN
(2021)
Article
Computer Science, Interdisciplinary Applications
Ming Li, Yongcun Song, Xingtong Yang, Kai Zhang
Summary: An optimization method is proposed for designing multi-lattice structures with local buckling constraints. A consecutive numerical approach, including macro-field optimization and microstructure embedding, is devised to solve the highly nonlinear large-scale optimization problem. The macro-field optimization finds an optimal elasticity tensor distribution, while an inverse design approach approximates the elasticity tensor under local buckling constraint to embed an appropriate lattice structure. A machine learning approach is used to reduce the number of material/lattice types and computational costs. Numerical examples demonstrate the production of a lattice structure meeting the requirements of overall stiffness and local buckling resistance.
COMPUTERS & STRUCTURES
(2023)
Article
Thermodynamics
Mohamad Modrek, Asha Viswanath, Kamran A. Khan, Mohamed I. Hassan Ali, Rashid K. Abu Al-Rub
Summary: This study designs thermal heat sinks using topology optimization and maps porous cellular structures to gyroid-based heat sinks using unique mapping approaches. The thermal performance, such as thermal conductivity, of the optimized heat sinks is analyzed, and the heat transfer capabilities of the mapped structures are compared.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Engineering, Manufacturing
Mirhan Ozdemir, Ugur Simsek, Gullu Kiziltas, Cemal Efe Gayir, Alican Celik, Polat Sendur
Summary: Triply periodic minimum surface (TPMS) lattice structures have gained interest in engineering applications due to their excellent mechanical properties. Hybridization of different lattice types is proposed to enhance the design performance. In this study, a hybrid optimization scheme based on genetic algorithms and anisotropic homogenization-based topology optimization is applied to a MBB beam design. The best lattice morphology is identified using GA and then further optimized using homogenization-based topology optimization. The graded multi-morphology lattice is reconstructed using a blending algorithm and manufactured using the DMLM technique. Experimental results show that the stiffness of the graded multi-morphology structure is higher than the graded and uniform single lattice morphologies.
ADDITIVE MANUFACTURING
(2023)
Article
Mechanics
Taehoon Jung, Jaewook Lee, Tsuyoshi Nomura, Ercan M. Dede
Summary: This paper presents a three-dimensional topology optimization for the inverse design of unidirectional fiber reinforced composite structures, including the co-design of composite macrostructure, spatially-varying fiber size, and orientation. The effectiveness of the proposed design scheme is validated through three design examples for compliance minimization and compliant mechanism problems.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Manufacturing
Quang Thang Do, Cong Hong Phong Nguyen, Young Choi
Summary: A method for cellular structure design based on homogenization and Voronoi tessellation is proposed, improving structural stability and robustness while reducing computation costs.
ADDITIVE MANUFACTURING
(2021)
Article
Biophysics
Brian Chang, Chelsea Reighard, Colleen Flanagan, Scott Hollister, David Zopf
JOURNAL OF BIOMECHANICS
(2020)
Article
Multidisciplinary Sciences
Harsha Ramaraju, Loran D. Solorio, Martin L. Bocks, Scott J. Hollister
Review
Chemistry, Multidisciplinary
Harsha Ramaraju, Ryan E. Akman, David L. Safranski, Scott J. Hollister
ADVANCED FUNCTIONAL MATERIALS
(2020)
Article
Endocrinology & Metabolism
Brett S. Klosterhoff, Jarred Kaiser, Bradley D. Nelson, Salil S. Karipott, Marissa A. Ruehle, Scott J. Hollister, Jeffrey A. Weiss, Keat Ghee Ong, Nick J. Willett, Robert E. Guldberg
Article
Engineering, Biomedical
Julia R. Brennan, Ashley Cornett, Brian Chang, Sarah J. Crotts, Zahra Nourmohammadi, Isabelle Lombaert, Scott J. Hollister, David A. Zopf
Summary: Auricular reconstruction is a complex procedure that requires surgical expertise, with 3D printing offering a potential solution to reduce technical demands. A study comparing single- and two-stage 3D-printed auricular tissue scaffolds in a rodent model showed promising results, with precise anatomical appearance and maintenance of integrity of the auricular surfaces. No significant differences in complications were noted between the two implantation methods, indicating the potential for future clinically viable options for ear tissue scaffolds.
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS
(2021)
Article
Engineering, Biomedical
Harsha Ramaraju, Anum Ul-Haque, Adam S. Verga, Martin L. Bocks, Scott J. Hollister
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2020)
Article
Medicine, Research & Experimental
Brian Chang, Ashley Cornett, Zahra Nourmohammadi, Jadan Law, Blaine Weld, Sarah J. Crotts, Scott J. Hollister, Isabelle M. A. Lombaert, David A. Zopf
Summary: The study evaluated the use of 3D-printed auricular scaffolds with and without cartilage inserts in a rodent model, showing that adding cartilage inserts can enhance clinical and histological outcomes.
Article
Dentistry, Oral Surgery & Medicine
Shelly Abramowicz, Sarah Jo Crotts, Scott J. Hollister, Steve Goudy
Summary: This study developed a proof-of-principle porcine model for pediatric TMJ mandibular condyle reconstruction using a customized 3D-printed scaffold coated with BMP-2 implanted in vascularized temporalis muscle. The results showed that the reconstructed side maintained appropriate condylar height and generated new bone, although the stiffness was lower compared to the control side.
ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY ORAL RADIOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Ryan Akman, Harsha Ramaraju, Scott J. Hollister
Summary: A UV-curable polymer (APGD) developed from acrylation of PGD is described, eliminating the need for thermal curing while maintaining shape memory properties. The control of APGD's properties across different acrylation percentages and molecular weights is shown. The biocompatibility of APGD is demonstrated through in vitro assays, and its potential in 3D printing for patient-specific devices in minimally invasive procedures is highlighted.
ADVANCED ENGINEERING MATERIALS
(2021)
Article
Engineering, Biomedical
Harsha Ramaraju, Kishan Pithadia, Sarah J. Crotts, Colleen L. Flanagan, Glenn E. Green, Scott J. Hollister
Summary: This study investigated the impact of print direction and part size on the material and structural properties of laser-sintered PCL parts, finding that larger parts and parts printed in the XY direction had greater effective moduli, in alignment with void volumes associated with print direction and size. By evaluating microstructural properties and selecting effective moduli based on manufacturing parameters, accurate prediction of device performance can be achieved.
ANNALS OF BIOMEDICAL ENGINEERING
(2021)
Article
Engineering, Biomedical
Jeong Hun Park, Minjun Ahn, Sun Hwa Park, Hyeonji Kim, Mihyeon Bae, Wonbin Park, Scott J. Hollister, Sung Won Kim, Dong-Woo Cho
Summary: An advanced extrusion-based 3D bioprinting strategy was developed to create a clinically-sized cellular construct mimicking a trachea. A two-step printing process, including a porous bellows framework and selective printing of cellular components, significantly reduced total printing time and demonstrated potential for clinical application.
Article
Otorhinolaryngology
Ross Michaels, Harsha Ramaraju, Sara J. Crotts, Scott J. Hollister, David A. Zopf
Summary: This study introduced a novel polycaprolactone scaffold designed through 3D printing, which successfully expanded cricoid cartilage in a porcine model. Post-operative evaluations showed no signs of implant instability and successful mucosalization over the scaffold. The study demonstrated early success and potential for further evaluation in larger animal studies.
INTERNATIONAL JOURNAL OF PEDIATRIC OTORHINOLARYNGOLOGY
(2021)
Article
Engineering, Biomedical
Marley J. Dewey, Derek J. Milner, Daniel Weisgerber, Colleen L. Flanagan, Marcello Rubessa, Sammi Lotti, Kathryn M. Polkoff, Sarah Crotts, Scott J. Hollister, Matthew B. Wheeler, Brendan A. C. Harley
Summary: While there were no differences in overall healing response between the mineralized collagen-PCL composites and the PCL mesh in a critical-sized porcine ramus defect model, data showed variability in metrics of healing, with some implants surrounded by abscesses and PCL polymer still present after 9-10 months. Some implants demonstrated substantial levels of bone regeneration, suggesting targeted improvements are necessary for repair of large animal models to better represent CMF bone healing. Strategies for enhancing osteogenesis, modulating the immune system, and improving scaffold properties may be beneficial for successful bone regeneration.
Article
Cardiac & Cardiovascular Systems
Anthony Y. Tsai, Morgan K. Moroi, Andrea S. Les, Scott J. Hollister, Glenn E. Green, Robert E. Cilley, Peter Dillon, Joseph B. Clark
Summary: Tracheal agenesis (TA) is a rare and typically fatal congenital malformation, with only about 150 reported cases and near-universal lethality. Patients with TA typically present with cyanosis, respiratory distress, and aphonia. Extended survival in patients with TA can be achieved through esophageal airway reconstruction using an externally supported 3D-printed bioresorbable splint.
Article
Surgery
Chelsea L. Reighard, Allison R. Powell, Sarah Jo Crotts, Scott J. Hollister, Jennifer Kim, David A. Zopf
FACIAL PLASTIC SURGERY & AESTHETIC MEDICINE
(2020)