scholarly journals Ablative Laser Structuring for Stretchable Multilayer and Multi-Material Electronics and Sensor Systems

Proceedings ◽  
2020 ◽  
Vol 56 (1) ◽  
pp. 21
Author(s):  
Simon P. Stier ◽  
Holger Böse

Conventional machining and shaping processes for polymers and elastomers such as injection molding exhibit significant disadvantages, as specific tools have to be manufactured, the method of machining is highly dependent on the material properties, and the cost of automation is usually high. Therefore, additive manufacturing processes (3D printing) have established themselves as an alternative. This eliminates the expensive production of tools and the production is individualized. However, the specific (additive) manufacturing process remains highly dependent on the properties of the material. These processes include selective laser sintering (SLS) for powdered thermoplastic polymers and metals, extrusion such as fused deposition modeling (FDM) for thermoplastic polymers in wire form, or optical curing such as digital light processing (DLP) for liquid resins. Especially for elastomer sensors or circuit boards (structure of several alternately constituted approx. 100 µm-thick elastomer films made with different types of liquid silicone rubber), there is no suitable additive manufacturing process that combines liquid, partly non-transparent source materials, multi-component printing, and very fine layer thicknesses. In order to enable a largely automated, computer-aided manufacturing process, we have developed the concept of ablative multilayer and multi-material laser-assisted manufacturing. Here, the layers (conductive and non-conductive elastomers, as well as metal layers for contacting) are first coated over the entire surface (e.g., spray, dip, or doctor blade coating, as well as galvanic coating) and then selectively removed with a CO2 or fiber laser. These steps are repeated several times to achieve a multi-layer structured design. Is it not only possible to adjust and improve the work previously carried out manually, but also to introduce completely new concepts, such as fine through-plating between the layers to enable much more compact structures to be possible. As an exemplary application, we have used the process for manufacturing a thin and surface solderable pressure sensor and a stretchable circuit board.

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1946 ◽  
Author(s):  
Héctor García-Martínez ◽  
Ernesto Ávila-Navarro ◽  
Germán Torregrosa-Penalva ◽  
Alberto Rodríguez-Martínez ◽  
Carolina Blanco-Angulo ◽  
...  

This work presents a study on the implementation and manufacturing of low-cost microwave electronic circuits, made with additive manufacturing techniques using fused deposition modeling (FDM) technology. First, the manufacturing process of substrates with different filaments, using various options offered by additive techniques in the manufacture of 3D printing parts, is described. The implemented substrates are structurally analyzed by ultrasound techniques to verify the correct metallization and fabrication of the substrate, and the characterization of the electrical properties in the microwave frequency range of each filament is performed. Finally, standard and novel microwave filters in microstrip and stripline technology are implemented, making use of the possibilities offered by additive techniques in the manufacturing process. The designed devices were manufactured and measured with good results, which demonstrates the possibility of using low-cost 3D printers in the design process of planar microwave circuits.


2016 ◽  
Vol 674 ◽  
pp. 9-14 ◽  
Author(s):  
Piret Mägi ◽  
Andres Krumme ◽  
Meelis Pohlak

This study explores possible ways to make Additive Manufacturing (AM) a cradle-to-cradle process, that is, use the leftover from one process as the raw material for another process. The main goal of this study is to develop a set of new polymeric blends with innovative properties, suitable for using in 3-D printing of prosthetic limbs using Fused Deposition Modeling (FDM) technology. Sustainable acting is achieved by reusing polymeric material left over from Selective Laser Sintering (SLS) processes for making raw material for FDM processes. Test specimens of polyamide 12 (PA-12) in its virgin form and used- , un-sintered form alongside specimens of used PA blended with TPU, aramid, or graphite, were produced in a micro-injection moulding machine and then tested for their mechanical properties. This paper provides information about the differences in mechanical characteristics of these different material blends. An unexpected but positive finding was that the differences between virgin and recycled PA-12 are insignificant. The aforementioned additives influenced PA-12 by producing specimens that responded with predictable characteristics which is a significant accomplishment as it lays the groundwork for the next stages of the project.


Author(s):  
Leonardo Portilha Gomes da Costa ◽  
Stephanie Isabel Díaz Zamalloa ◽  
Fernando Amorim Mendonça Alves ◽  
Renan Spigolon ◽  
Leandro Yukio Mano ◽  
...  

3D printers manufacture objects used in various dental specialties. Objective: This literature review aims to explore different techniques of current 3D printers and their applications in printed materials for dental purposes. Methods: The online PubMed databases were searched aiming to find applications of different 3D printers in the dental area. The keywords searched were 3D printer, 3D printing, additive manufacturing, rapid prototyping, 3D prototyping, dental materials and dentistry. Results: From the search results, we describe Stereolithography (SLA), Digital Light Processing (DLP), Material Jetting (MJ), Fused Deposition Modeling (FDM), Binder Jetting (BJ) and Dust-based printing techniques. Conclusion: 3D printing enables different additive manufacturing techniques to be used in dentistry, providing better workflows and more satisfying clinical results.


Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2540 ◽  
Author(s):  
José Linares-Alvelais ◽  
J. Figueroa-Cavazos ◽  
C. Chuck-Hernandez ◽  
Hector Siller ◽  
Ciro Rodríguez ◽  
...  

In this work, we assess the effects of sterilization in materials manufactured using additive manufacturing by employing a sterilization technique used in the food industry. To estimate the feasibility of the hydrostatic high-pressure (HHP) sterilization of biomedical devices, we have evaluated the mechanical properties of specimens produced by commercial 3D printers. Evaluations of the potential advantages and drawbacks of Fused Deposition Modeling (FDM), Digital Light Processing (DLP) technology, and Stereolithography (SLA) were considered for this study due to their widespread availability. Changes in mechanical properties due to the proposed sterilization technique were compared to values derived from the standardized autoclaving methodology. Enhancement of the mechanical properties of samples treated with Hydrostatic high-pressure processing enhanced mechanical properties, with a 30.30% increase in the tensile modulus and a 26.36% increase in the ultimate tensile strength. While traditional autoclaving was shown to systematically reduce the mechanical properties of the materials employed and damages and deformation on the surfaces were observed, HHP offered an alternative for sterilization without employing heat. These results suggest that while forgoing high-temperature for sanitization, HHP processing can be employed to take advantage of the flexibility of additive manufacturing technologies for manufacturing implants, instruments, and other devices.


2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Youwen Yang ◽  
Guoyong Wang ◽  
Huixin Liang ◽  
Chengde Gao ◽  
Shuping Peng ◽  
...  

Additive manufacturing (AM) can obtain not only customized external shape but also porous internal structure for scaffolds, both of which are of great importance for repairing large segmental bone defects. The scaffold fabrication process generally involves scaffold design, AM, and post-treatments. Thus, this article firstly reviews the state-of-the-art of scaffold design, including computer-aided design, reverse modeling, topology optimization, and mathematical modeling. In addition, the current characteristics of several typical AM techniques, including selective laser sintering, fused deposition modeling (FDM), and electron beam melting (EBM), especially their advantages and limitations are presented. In particular, selective laser sintering is able to obtain scaffolds with nanoscale grains, due to its high heating rate and a short holding time. However, this character usually results in insufficient densification. FDM can fabricate scaffolds with a relative high accuracy of pore structure but with a relative low mechanical strength. EBM with a high beam-material coupling efficiency can process high melting point metals, but it exhibits a low-resolution and poor surface quality. Furthermore, the common post-treatments, with main focus on heat and surface treatments, which are applied to improve the comprehensive performance are also discussed. Finally, this review also discusses the future directions for AM scaffolds for bone tissue engineering.


Author(s):  
Ю. Б. Витязев ◽  
А. Г. Гребеников ◽  
А. М. Гуменный ◽  
А. М. Ивасенко ◽  
А. А. Соболев

The analysis of the most applicable in mechanical engineering additive technologies (fused deposition modeling, selective laser sintering, laser stereolithography, direct metal laser sintering) have been performed. Method of creating airplane models using CAD/CAM/CAE systems and additive manufacturing is presented. The results of the application of selective laser sintering and fused deposition modeling for the manufacture of training aircraft models are considered.


2019 ◽  
Vol 890 ◽  
pp. 113-145
Author(s):  
Imran Khan ◽  
Christina S. Kamma-Lorger ◽  
Saeed D. Mohan ◽  
Artur Mateus ◽  
Geoffrey R. Mitchell

Additive manufacturing (AM) is a well-known technology for making real three dimensional objects, based on metal, ceramic and plastic material used for various applications. The aim of this review is to explore and offer an insight in to the state of the art polymer based nanocomposites in to additive manufacturing applications. In context to this, the developing efforts and trends in nanocomposites development particularly for additive manufacturing processes were studied and summed up. The scope and limitations of nanocomposites into Stereolithography, selective laser sintering and fused deposition modeling was explored and highlighted. The review highlights widely accepted nanoparticles for range of applications including mechanical, electrical, flame retardance and crossing over into more biological with the use of polymer matrices. Acquisition of functional parts with limitations in regard to printing is highlighted. Overall, the review highlights successes, limitations and opportunities that the union of AM and polymer based nanocomposites can bring to science and technology.


2010 ◽  
Vol 2010 (1) ◽  
pp. 000940-000946 ◽  
Author(s):  
Richard Olivas ◽  
Rudy Salas ◽  
Dan Muse ◽  
Eric MacDonald ◽  
Ryan Wicker ◽  
...  

Implementing electronics systems that are conformal with curved and complex surfaces is difficult if not impossible with traditional fabrication techniques, which require stiff, two dimensional printed circuit boards (PCB). Flexible copper based fabrication is currently available commercially providing conformance, but not simultaneously stiffness. Consequently, these systems are susceptible to reliability problems if bent or stretched repeatedly. The integration of Additive Manufacturing (AM) combined with Direct Print (DP) micro-dispensing can provide shapes of arbitrary and complex form which incorporate 1) miniature cavities for insetting electronic components and 2) conductive traces for electrical interconnect between components. The fabrication freedom introduced by AM techniques such as stereolithography (SL), ultrasonic consolidation (UC), and fused deposition modeling (FDM) have only recently been explored in the context of electronics integration. Advanced dispensing processes have been integrated into these systems allowing for the introduction of conductive inks to serve as electrical interconnect within intricately-detailed dielectric structures. This paper describes a process that provides a novel approach for the fabrication of stiff conformal structures with integrated electronics and describes several prototype demonstrations: a body conformal helmet insert for detection of Traumatic Brain Injury (TBI), a 3D magnetic flux sensor with LED indicators for magnitude and direction and a floating sensor capable of detecting impurities in water while maintaining orientation through density gradients.


2019 ◽  
Vol 25 (11) ◽  
pp. 1249-1264 ◽  
Author(s):  
Amoljit Singh Gill ◽  
Parneet Kaur Deol ◽  
Indu Pal Kaur

Background: Solid free forming (SFF) technique also called additive manufacturing process is immensely popular for biofabrication owing to its high accuracy, precision and reproducibility. Method: SFF techniques like stereolithography, selective laser sintering, fused deposition modeling, extrusion printing, and inkjet printing create three dimension (3D) structures by layer by layer processing of the material. To achieve desirable results, selection of the appropriate technique is an important aspect and it is based on the nature of biomaterial or bioink to be processed. Result & Conclusion: Alginate is a commonly employed bioink in biofabrication process, attributable to its nontoxic, biodegradable and biocompatible nature; low cost; and tendency to form hydrogel under mild conditions. Furthermore, control on its rheological properties like viscosity and shear thinning, makes this natural anionic polymer an appropriate candidate for many of the SFF techniques. It is endeavoured in the present review to highlight the status of alginate as bioink in various SFF techniques.


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