Topology Optimization of Metamaterials and Tissue Engineering Systems

Topology Optimization of Metamaterials and Tissue Engineering Systems

Güllü Kızıltaş
Multifunctionality via Automated Design and Realization From Scratch

Materials being one of the last frontiers in design, the goal at SU is to develop new phenomena and novel system properties by design, analysis and fabrication of artificially engineered materials. When applied to EM components, this implies the automated manipulation of the dielectric [?] and magnetic [?] material matrices to achieve desired multifunctionality.

Automated Design and Fabrication of Material Based Complex Systems

Dr. Kiziltas’ research addresses the challenges of system design from an interdisciplinary engineering perspective, with a focus on using automated design tools (such as topology optimization) and artificially engineered composite materials. The development of artificial materials with new features has been a key to the spectacular technological advances of the last decades. In particular, in addition to the analysis and synthesis of materials with special electric and magnetic properties, their fabrication and characterization are topics of high strategic relevance, in view of their potential impact on a variety of leading edge technologies, including not only telecommunications but also aerospace, RF-MEMS, biomedical engineering and the science of materials. Advances in the research topics of Dr. Kiziltas group will allow, for the first time, integration of the best simulation tools and design algorithms to generate totally novel and yet unthinkable designs that will lead to a new paradigm in design. This goal being the essence of her research group, the outcome of these investigations will have tremendous impact on not only microwave devices such as multifunctional novel antennas but also on energy and biomedical applications.

I) Design and fabrication of novel composite substrates for electromagnetic applications

The analysis and synthesis of complex electromagnetic material, poses a four-fold challenge of developing novel modeling, design, characterization and fabrication tools. Dr. Gullu Kiziltas and her group focuses on designing new material and conductor topologies for novel electromagnetic materials and their realization with off the shelf dielectrics- primarily ceramic-ceramic composites and ceramic-polymer composites.

a) Inverse synthesis of 3D spectral metamaterials for RF and nano-applications Figure: Optimal designed and fabricated anisotropic electromagnetic material with off the shelf dielectric constituents

With specific reference to electromagnetic applications, the possibility of obtaining new materials with prescribed anisotropy, dispersion and nonlinearity over a wide frequency band is of utmost importance.

b) Design and fabrication of deformable antenna substrates

In a variety of key problems, the research approach pays attention in bridging synthesis/analysis (engineering) with practical realization (materials science) of complex devices which leads to the broader definition of the research theme as the “Automated Design and Realization of Complex Material Systems”

Hence, the primary objective of Dr. Kiziltas is to understand, design and optimize new materials and composites and finally fabricate them with desired new properties for device performance enhancements and/or miniaturization purposes. A clear understanding of engineered composites requires an interdisciplinary thought process, grounded in a sound fundamental knowledge of traditional composite materials and a powerful design tool.

Figure: Fabricated deformable polymer-ceramic functionally graded substrates using tape casting (left) and freeze drying (right)

II) Design and fabrication of novel composite substrates for biomedical applications

The group’s recent efforts focus on expanding their electromagnetic research expertise to cover the design and fabrication of artificial tissues in particular bone tissues.

a) Topology design and fabrication of multi-functional artificial bone tissues Figure: Fabricated deformable polymer-ceramic functionally graded substrates using tape casting (left) and freeze drying (right)

Tissue engineering plays a critical role in regenerative medicine. Advances in TE and regenerative medicine will depend on the design and fabrication of “multifunctional” biomaterials that actively participate in the formation of functional tissues such as bones. Dr. Gullu Kiziltas is working on the automated design of artificial bone tissues using topology optimization based techniques. She is also interested in their fabrication using advanced 3D fabrication methodologies as well as their modeling based on micro-CT characterization. Clinical translation of this computational automated realization of novel biomaterials is expected to support the healing processes of tissues in a much more effective way.

b) micro-CT characterization and analysis of biomedical tissues
Figure: Micro-CT images of GAG-mimetic peptide nanofiber gel treated and regenerated bone defects in rabbit tibia bone (left) and root canals that received different posts (right)

Therefore, more recently the group collaborated together with scientists from Medical School, Biology, Dentistry and Physics from and outside the university and colleagues to meet these objectives by expanding their previous research expertise to cover micro-CT characterization and analysis of biomedical tissues.

III) Multi-Disciplinary Design Optimization (MDO) of complex systems Figure Co-design framework for variable stiffness actuators developed in collaboration with Dr. Patoglu

Development of multi-disciplinary design optimization platforms has become crucial to satisfy stringent performance expectations for many complex systems such as aircrafts, automotive and similar. Being multidisciplinary systems, performance of such devices cannot be fully exploited unless MDO techniques that account for their inherent design couplings are employed for their optimization. Design of best performing engineering systems necessitates a good understanding and optimal utilization of interactions among their disciplinary design components. These interactions, also known as design couplings, have been defined as the design interrelationships among engineering disciplines within a multidisciplinary system. Robotic systems similar to many mechatronic systems are examples of controlled mechanical systems that require both the design of a mechanism—often referred to as a “plant” and a controller. In collaboration with Dr. Patoglu, Dr. Kiziltas focuses on the development of co-design frameworks to robotic systems such as a VSA in an effort to move towards systems having otherwise unattainable levels of performance.