Hoc Khiem Trieu
on behalf of
Hoc Khiem Trieu (Germany) 3D patterning: An extended toolbox for MEMS
Microsystems, also known as MEMS (Micro Electro Mechanical Systems), originated from the Semiconductor Technology which is a typical subtractive planar technology for the fabrication of microelectronic devices and integrated circuits. Extended by specific process modules like surface and bulk micromachining 3D freely moveable structures have been realized. However, achievable patterns are limited to 2D and 2.5D due to the processes in use like photolithography, thin film deposition and deep reactive ion etching. MEMS are well established and indispensable in daily life, with high potential in life sciences. Grey tone lithography has enabled the transfer of 3D patterns from a resist mask into the substrate. MEMS with complex structures as microvalves and micropumps have been implemented by bulk micromachining in combination with wafer bonding techniques. However, real 3D structures with high degree of design freedom as known from additive manufacturing are not yet available in MEMS.
3D patterning with additive manufacturing like photo polymerization, extrusion, powder bed fusion or direct writing and subtractive approaches like selective laser-induced etching are highly versatile manufacturing techniques differing in technology, materials and precision. Other benefits apart from high degree of design freedom are efficiency and customization. However, complexity of 3D printed devices is still limited. Recent trends in multi-material additive manufacturing demonstrate more complex 3D printed parts with interesting applications for printed electronics. Nevertheless, the complexity and integration density of MEMS remain unmet.
A hybrid approach for the integration of 3D patterning techniques as an extended toolbox for wafer-level fabrication of 3D MEMS including photonic waveguides is presented here. Compatibility of 3D printing and MEMS is considered with respect to their resolution respectively precision in the micrometer and sub-micrometer range as well as the capability to create intimate contacts between a patterned wafer and the 3D printed structures. Two high-precision 3D patterning techniques, selective laser-induced etching (SLE) and two photon polymerization (2PP), have been studied for 3D MEMS like e.g. a GVDN nozzle (gas dynamic virtual nozzle. Additionally, an ultra-high precision direct printing method for the direct writing of metals and dielectrics on 3D surfaces has been investigated. The application of a strategy using well defined process flows with repetition of process steps from the toolbox, going beyond the single-step manufacturing approach of current 3D printing methods, will enable the fabrication of more complex integrated 3D MEMS.
Hoc Khiem Trieu studied physics at RWTH Aachen University and subsequently received his PhD in electrical engineering from the University of Duisburg-Essen in 1997, focusing on the structuring of silicon for the development of 3D microsystems. From 1999 to 2007, he headed the R&D group Sensor Technology at the Fraunhofer Institute for Microelectronic Circuits and Systems (IMS) in Duisburg, where he established the department Integrated Sensor and Actuator Technology and was responsible for it from 2008 until early 2011, before accepting the call to the Hamburg University of Technology (TUHH) in March 2011. At TUHH, Hoc Khiem Trieu heads the Institute of Microsystems Technology. He is initiator and spokesperson of Forschungslabor Mikroelektronik Deutschland ForLab HELIOS for Co-Integration of Photonics and Electronics as well as spokesperson of Hamburg Research Center for Medical Engineering fmthh.
Sabine Fuchs (Germany): Bone Tissue Reconstruction: From Cellular Self-Assembly to 3D (Bio)Printing
Successful bone tissue reconstruction needs to take into account multiple aspects ranging from the selection of biocompatible implant materials to complex biological mechanisms guiding bone tissue repair. All these factors are also essential for new additive manufacturing technologies such as 3D (bio)printing of bone constructs. So far mainly acellular material based 3D constructs are generated by 3D printing. In this context this presentation will emphasize how 3D printing technologies can profit from the cellular interaction during bone repair and vascularization leading to self-assembly of vascularized bone tissue in 3D bone constructs. In combination with 3D manufacturing technologies such as extrusion based printing and digital light processing technologies, this will enable to generate larger complex bone constructs in the future. First steps are made in bone tissue reconstruction by bioprinting including the development of bioinks and solid bone scaffolds. However, complex technological challenges still exist and need to addressed by interdisciplinary approaches in the future.
Sabine Fuchs studied biology and finished her PhD in 2003 at the Department of Biopharmaceutics and Phamaceutical Technology at the Saarland University, Germany. From 2003 to 2011 she was working as post doc and group leader of a „German-Chinese Young Investigator Group“ at the Institute of Pathology, University Medical Department in Mainz, Germany. After her „Habilitation“ in Molecular Medicine in 2011, she moved to the University Medical Center Schleswig-Holstein and accepted a professorship for Experimental Trauma Surgery at Department of Orthopedics and Trauma Surgery in Kiel. Her research interests comprise: the impact of implants on cellular and molecular processes guiding bone healing, biocompatibility of biomaterials, mechanisms and cellular interaction involved in bone repair, trauma research, as well as bioprinting of tissue constructs.
Luca Carnevali (Belgium): Personalization of radiotherapy with VSP Bolus
Radiotherapy is a treatment modality used in approximately half of all cancer cases to target and kill cancerous cells [1,2]. Many treatment options require the use of a bolus which attenuates the radiation beam to alter the dose at desired tissue depths. A common clinical solution is a silicone slab, which is placed on the patient’s targeted treatment anatomy to act as a bolus. However, patient-specific boluses have shown in improvement in patient conformality and have shown improved radiotherapy plan dose conformity . As such, 3D Systems developed VSP® Bolus to offer an FDA-cleared, elastomeric, 3D-printed, and patient-specific solution for radiation oncology. The VSP Bolus workflow begins with the submission of patient CT data through a physician-facing portal. Using, DICOM-to-Print (D2P®) software, the patient’s skin tissue is segmented into a 3D model. Biomedical engineers use information from the radiotherapy treatment plan and the patient 3D model to create a uniform thickness bolus using Geomagic® Freeform®, a volumetric modeling software tool specializing in non-parametric patient contours. The patient-specific bolus is optimized for 3D printing in 3D Sprint®, 3D Systems’ build preparation software. The boluses are manufactured in an elastomeric material, VisiJet® M2E-BK70, on the ProJet® MJP 2500 Plus, a MultiJet system leveraging wax supports and picolitre quantities of jetted material resulting in high accuracy prints. VisiJet M2E-BK70 is the chosen material for the bolus application because of the material’s biocompatibility and elasticity (Shore A hardness of 70). Because the device is in contact with patient tissue, VSP Bolus was evaluated for biocompatibility against ISO 10993-1:2018, Biological evaluation of medical device – Part 1: Evaluation and testing within a risk management process. The elastomeric, patient-matched, and biocompatible bolus is designed to improve patient treatment and set-up. As a healthcare solutions provider, 3D Systems leveraged expertise in patient-specific device manufacturing workflows, materials, 3D printing processes, and medical regulatory requirements to develop a physician-centric service. The service model enables clinicians to use an FDA-cleared patient-specific bolus for their oncology cases with limited device design burden.
Luca Carnevali is a Business Development Manager in the Healthcare business unit of 3D Systems. He obtained his Master of Science in Biomedical Engineering at the Polytechnic University of Turin and he focused his studies in Medical Device development and Additive Manufacturing. His role in 3D Systems focuses on providing solutions to OEMs, Service Providers and Research Entities for the development of new Medical Devices, exploiting the advantages of Additive Manufacturing technologies applied to Healthcare. Orthopedics, Spinal and Cranio-Maxillofacial surgery are just part of his fields of competence, since the rapid evolution of Additive Manufacturing allows him to continuously explore new markets. In fact, he has a strong focus also on Patient-Specific devices and Personalized Medicine solutions, which are indeed among the most advanced and promising fields of application of 3D Printing.
Lennart Schulenburg (Germany): Are my parts safe? Quality control in AM
Advanced manufacturing technologies like Additive Manufacturing (AM) are promising a substantial improvement in terms of production costs, part weight and freedom of design. This makes the new technologies highly attractive for all high-performance sectors from aerospace to automotive. As AM has matured into a viable manufacturing option in the recent years, business-plans are becoming more attractive. Now is the time to take a close look at the complete process chain to assess risks and potential obstacles before substantial investments are made. An often-overlooked aspect is the quality control and qualification of parts produced by AM processes. Are internal quality standards fit for the new manufacturing processes?
Is the right inspection equipment in place and does the team possess the right qualification? Is the part design suited for an effective inspection? These are questions that must be asked early on and must be addressed professionally – especially in safety-critical environments. A failure to do so could lead to severe complications at a stage where significant amounts of resources have been already invested. This presentation will provide an overview about the quality challenges related to Additive Manufacturing through a set of representative examples. It will highlight key aspects to consider when making design choices. “Design to manufacture” is well known in the field of AM design, but “Design for inspection” is equally important. Engineers, managers, and designer will get guidance on available inspection options and quality standards. Advanced manufacturing and especially AM are great technologies with an amazing potential. Addressing quality and qualification related obstacles early on will ensure that your projects will be successful and help to prevent costly failures.
Lennart Schulenburg is an author and expert in Non Destructive Testing (NDT) and quality control. As Managing Director of the X-Ray innovator VisiConsult X-ray Systems & Solutions from Northern Germany, he has a extensive experience in industries ranging from automotive to aerospace. VisiConsult was founded in 1996 and is the leading supplier of digital X-ray and Computed Tomography solutions to customers worldwide. With a degree in Computational Informatics and a MBA, he successfully initiates insightful technology development and is a regular speaker at industry events to share the latest trends and innovations in quality control and impact on the broader organization.
Björn Petersen (Germany): Mass personalization: From data analysis to print – and how AI helps
Personalization is quickly becoming an expectation in many industries. Driven by digitization, companies increasingly offer personalized solutions tailored to the user in the form, fit, or function. Within healthcare, personalization is driven by the desire to address unmet clinical needs and the ambition to tackle the healthcare system’s massive challenges. Medical device treatments can leverage technological innovations in 3D printing, artificial intelligence, or mixed reality to accelerate the level of personalization within patient care. Specifically, AI-based data analysis opens the doors to disruption in the medical device field by offering entirely new personalization avenues. Driven by creating cost-effective and sustainable solutions that better answer clinical challenges, targeted investments in infrastructure, software, knowledge, and partnerships are already making mass personalization a reality.
Materialise has gathered insight from its 30-year history to demonstrate the medical device industry’s progress and opportunity. We determined that five pillars must be addressed in order to realize the benefits of mass personalization in support of the healthcare industry at large: Health Economics & Regulation; Next-Generation 3D Printed Devices, Cost-Effective & Scalable Operations; Predictive Planning, and Personalization at the Point-of-Care.
Björn Petersen is Head of Sales of the Materalise Medical in Germany, Austria, Switzerland and Italy. Together with his expertised team of account managers and application engineers, he represents the 3D technology offering of Materialise Medical, which has pioneered many of the leading medical applications of 3D technology. The portfolio of Materialise Medical enables researchers, engineers and clinicians to revolutionize innovative patient-specific treatment that helps improve and save lives. Materialise Medical’s open and flexible platform of software and services, Materialise Mimics, forms the foundation of certified Medical 3D printing, in clinical as well as research environments, offering virtual planning software tools, 3D-printed anatomical models, and patient-specific surgical guides and implants. For additional information, please visit: medical.materialise.com
Jan Wilkes (Germany): Pushing the Limits of Metal Additive Manufacturing
Selective Laser Melting is an additive manufacturing technique that allows for producing high quality metal parts by selectively melting metal powder with laser beams. First commercial selective laser melting machines were equipped with a single laser beam source of comparably low power. That resulted in very limited build-up rate and therefore long production time and high production cost even for small parts. In the last years, SLM Solutions has constantly worked on increasing the build-up rate and productivity of the machine systems and has increased the build envelope size, in order to enable customers to build parts faster and at lower cost per part. The latest result of that effort is the NXG XII 600 machine, which includes 12 lasers with 1 kW output power each. This machine is moving the limits of achievable build-up rates and is the fastest SLM® / LPBF machine that is commercially available.
Another example where current limitations of metal additive manufacturing can be overcome is multi-material SLM® technology. SLM Solutions works on developing a technology for producing parts out of two different materials at the same time. That way the specific properties of each of the two materials can be combined in one part.
Jan Wilkes is Chief Engineer and Head of New Technology at SLM Solutions Group AG. SLM Solutions is a global provider of integrated metal additive manufacturing solutions. Jan Wilkes started working in the field of metal additive manufacturing almost 20 years ago. Stations of his career include Massachusetts Institute of Technology, Fraunhofer Institute for Laser Technology and Siemens Energy. He holds a PhD in mechanical engineering and an MBA from RWTH Aachen. With his team at SLM Solutions he contributes to the development of the most innovative production-oriented metal additive manufacturing systems.
Oliver Grimaldo Ruiz (Italy): An evaluation of bio-inspired patterns for soft tissue-mimicking with multi-material 3D-printing
Thanks to multi-material Additive manufacturing (AM), it is nowadays possible to mimic the mechanical behavior of complex biological soft tissues. This enables, e.g., to experiment with novel implantable devices or surgical procedures in a non-risk setting. In a recent work, the authors considered four bio-inspired patterns: Tendon-Like (TL), Tendon-Mimic (TM), Bamboo-Like (BL), and Helix-Bamboo (HB). Multi-material dog-bone specimens (designed accordingly to ASTM Standard D638, Type IV shape) were produced with a Stratasys® J750™ Digital Anatomy 3D Printer (DAP), combining Agilus30™ photopolymers with different Shore A hardness levels in several configurations. These included different matrix-to-fiber ratios, with the internal fibers arranged as complex layered structures (up to three layers). In total, 44 different variants were considered.
The properties of these specimens (three per variant) were then assessed under uniaxial Ultimate Tensile Strength (UTS) tests, performed at the Laboratory of Bio-inspired Nanomechanics of Politecnico di Torino. An MTS Insight® Electromechanical Testing System, specifically intended for the precise characterization of biological and bioinspired materials, was used, with a 100 N load cell. The results – in terms of stress-strain curves, tensile strength at break, maximum strain at break, and modulus of elasticity – were then compared to the values of the equivalent base PolyJet materials.
These comparisons showed that several patterns improved the mechanical response of the specimen with respect to their mono-material counterparts. For instance, at least one variant per each of the four classes (TL, TM, BL, and HB) returned a higher total deformation for comparable tensile strength. Thus, this work highlighted the potentialities of multi-material AM to integrate different hierarchical and complex shapes into single specimens. This enabling technology will play a decisive role for future biomedical applications, especially for soft tissue (e.g., tendon and ligament) repairing.
Oliver Grimaldo Ruiz was the winner of the Beca Nacional Colfuturo y Maestría double degree program (selected as one of the 1,258 best professionals of the Colombian government) in 2016. He obtained his bachelor's and master's degrees in Bioengineering and Biomedical Engineering (applied in Biomechanics and Bionanotechnology) from Universidad de Antioquia and Politecnico di Torino in 2017 and 2019 respectively. His master's thesis dealt with the development and 3D printing of multi-color and multi-material anatomical models of the knee joint in collaboration with Northwestern University and Shirley Ryan Ability Lab as a predoctoral fellow in 2018. subsequently, he worked as a research grant holder at the Bioinspired Nanomechanics Laboratory (Politecnico di Torino) until 2021. during his stay at the academy, He participated as a co-inventor in the development of a medical device for tendon and ligament repair in the proof of concept T-REM3DIE project in collaboration with Università Degli Studi di Trento and ASL Torino as well as he was involved in a Stratasys Ltd project for the development of a new ligament-like preset for the J750 DAP Polyjet printer. His expertise is in the fields of 3D modeling, additive manufacturing technologies, medical imaging, clinical workflows, finite element analysis, digital image correlation, and mechanical characterization of engineering materials. His work experience in academic settings, as well as in industry and hospital research in collaboration with orthopedists, complements his strong professional profile at Biomed.