Enhanced Scaffold Fabrication Techniques for Optimal Characterization
Naznin Sultana, Sanchita Bandyopadhyay-Ghosh, Chin Fhong Soon in Tissue Engineering Strategies for Organ Regeneration, 2020
Additive manufacturing (AM) is defined as a process where parts are fabricated layer-by-layer in an additive manner. The advancement of AM has enabled manufacturers to produce complex geometrical prototypes for rapid manufacturing. AM is a reliable process capable of providing low tooling costs, ease of fabrication, high accuracy and flexibility compared to other manufacturing processes such as CNC machining, molding or casting. The process begins by generation of solid 3D model using any computer aided engineering program. The computer aided drawing (CAD) file is converted to .STL (“Standard Triangle Language” or “Standard Tessellation Language”) file format before it is used by the AM machine. Various AM techniques have been utilized to produce tissue engineering scaffold including: stereolithography, fused deposition modelling, selective laser sintering, 3D printing and 3D plotting. These manufacturing processes have shown great stability to manufacture replicas with almost 100% of likeness.
Dentin-Pulp Complex Regeneration
Vincenzo Guarino, Marco Antonio Alvarez-Pérez in Current Advances in Oral and Craniofacial Tissue Engineering, 2020
Various techniques have been used to manufacture two- and three-dimensional scaffolds. The main technique to fabricate two-dimensional scaffolds is electrospinning; whereas the main techniques to fabricate three-dimensional scaffolds include solvent casting, freeze drying, particle/salt leaching, chemical/gas foaming, thermally induced phase separation and the foam-gel technique (Loh and Choong 2013; Lu et al. 2013; Park et al. 2015; Gomez-Lizarraga et al. 2017; Ortiz et al. 2017; Del Bakhshayesh et al. 2018; Granados-Hernandez et al. 2018; Vazquez-Vazquez et al. 2018; Xu et al. 2018). These techniques have some limitations to yield scaffolds with specific micro-architectures in terms of porosity, pore size, pore geometry and interconnectivity. They are still being used because of their low cost and minimal equipment complexity. Besides, due to their manufacturing conditions, these techniques do not allow including living cells or soluble factors within the process. Additive manufacturing techniques have arisen as a solution to these disadvantages. The most accepted of these techniques include: stereolithography, selective laser sintering, fused deposition modeling and three-dimensional printing (Moreno Madrid et al. 2019).
Bio-Implants Derived from Biocompatible and Biodegradable Biopolymeric Materials
P. Mereena Luke, K. R. Dhanya, Didier Rouxel, Nandakumar Kalarikkal, Sabu Thomas in Advanced Studies in Experimental and Clinical Medicine, 2021
Two components are needed for making biological implants. A bioprinter containing materials such as living cells which predetermine the 3D form for creating the organ and biochemical reactor in which the manufactured organ can mature in vitro. Organ printing is defined as a computer-aided processing which cells or cell-laden biomaterials are placed in the form of aggregates, which then serve as building blocks and are further assembled into a 3D functional organ. Solid objects with complex shapes are manufactured by additive manufacturing methods and referred as 3D printing. This is a method used to manufacture objects by making layers of material arranged one over the other to get the finished article. Fused deposition modeling (FDM) is an additive manufacturing method. Thin strands of molten thermoplastics materials are laid down on each other using a print-head controlled by a computer-aided design (CAD) software. The printed object will form when the material gets solidified over the print surface.
Emerging technologies and their potential for generating new assistive technologies
Published in Assistive Technology, 2021
Sarah Abdi, Irene Kitsara, Mark S. Hawley, L. P. de Witte
Additive manufacturing refers to the automated process creating a 3D object from a computer model, typically building the object through depositing layer upon layer of some malleable material. 3D printing is the most known, widely referenced example of additive manufacturing. It allows for effective, relatively cheap, and customized production of components leading to more appropriate and personalized AT products better suited to their users. Recent advances in additive manufacturing have extended the range of materials that can be used. Applications of additive manufacturing in AT are typically related to wheelchairs, walking aids and prostheses/orthoses, although there are examples of several other AT products or components produced by additive manufacturing. Prosthetics, orthotics, hearing aids and cochlear implants were examples of applications areas of additive manufacturing that were identified in the patent analysis. Some recent patent documents also referred to the use of titanium for 3D printing, which could open up possibilities where robustness and lightness are paramount (Lovells, 2017; Matos & Wiedemann, 2019; Switch, 2019).
Exploring new frontiers in drug delivery with minimally invasive microneedles: fabrication techniques, biomedical applications, and regulatory aspects
Published in Expert Opinion on Drug Delivery, 2023
Niha Sultana, Ayesha Waheed, Asad Ali, Samreen Jahan, Mohd Aqil, Yasmin Sultana, Mohd. Mujeeb
Additive manufacturing, a well-known 3D printing technology or Solid Freeform Fabrication, is a group of various different techniques that employs CAD model to develop an object by deposition of consecutive layers of polymers. This method is fast and produces accurate structures with complexity that are difficult using conventional techniques. CAD software is the first step in all additive manufacturing (AM) technologies (CAD). Afterward, the STL (Standard Tessellation Language) file is used to tessellate the 3D shape and slice it into digital layers in the second step. In order to transfer the STL file to the printer, custom machine software is used, and the printer is configured to print. Printing layers of appropriate material (e.g. ceramics, liquids, thermoplastics, plastics, photosynthetic polymers, powder, or even living cells) allows the printer to construct the model [62].
Advances in additive manufacturing processes and their use for the fabrication of lower limb prosthetic devices
Published in Expert Review of Medical Devices, 2023
Shaurya Bhatt, Deepak Joshi, Pawan Kumar Rakesh, Anoop Kant Godiyal
Traditionally prostheses are fabricated by assembling various standard components into one assembly that fulfills the required functionality. Some components are made by machining, while some are manufactured using the casting method, which requires a machining process to obtain the finished product. All these processes are not material efficient as raw material is wasted while machining. Moreover, the prostheses fabricated by the traditional method are standard prostheses that are not based on individual requirements and do not provide the utmost fit and comfort to the user. To overcome these shortcomings, the additive manufacturing processes can be used to get the desired fit and comfort as they can provide user-specific outputs. Prosthetic devices are specific to the type of amputation suffered by the person. For example, an above-knee prosthetic limb includes a transfemoral socket, an artificial knee, a pylon, a foot, and a few adaptors to attach these parts into one assembly [43]. A prosthetic device for below-knee amputation would include similar components except for the artificial knee. An above-knee prosthetic device assembly is shown in Figure 3, with components like an artificial knee, a damping device, transfemoral socket, foot, and adaptors. Some of the lower limb prosthesis developed by researchers are given in Figure 4 [3,44–61]. All these devices were developed by traditional methods.
Related Knowledge Centers
- Mental Model
- Photopolymer
- Selective Laser Sintering
- Stereolithography
- Ultraviolet
- Thermoplastic
- Thermosetting Polymer
- Ultraviolet Index
- Laser
- 3D Scanning