Organ printing can be defined as layer-by-layer additive robotic biofabrication of three-dimensional functional living macrotissues and organ constructs using tissue spheroids as building blocks. The microtissues and tissue spheroids are living materials with certain measurable, evolving and potentially controllable composition, material and biological properties. Closely placed tissue spheroids undergo tissue fusion - a process that represents a fundamental biological and biophysical principle of developmental biology-inspired directed tissue self-assembly. It is possible to engineer small segments of an intraorgan branched vascular tree by using solid and lumenized vascular tissue spheroids. Organ printing could dramatically enhance and transform the field of tissue engineering by enabling large-scale industrial robotic biofabrication of living human organ constructs with "built-in" perfusable intraorgan branched vascular tree. Thus, organ printing is a new emerging enabling technology paradigm which represents a developmental biology-inspired alternative to classic biodegradable solid scaffold-based approaches in tissue engineering.

Organ Printing: Tissue Spheroids as Building Blocks

Written for those who want to develop their knowledge of requirements engineering process, whether practitioners or students.Using the latest research and driven by practical experience from industry, Requirements Engineering gives useful hints to practitioners on how to write and structure requirements. It explains the importance of Systems Engineering and the creation of effective solutions to problems. It describes the underlying representations used in system modeling and introduces the UML2, and considers the relationship between requirements and modeling. Covering a generic multi-layer requirements process, the book discusses the key elements of effective requirements management. The latest version ofDOORS (Version 7)- a software tool which serves as an enabler of a requirements management process - is also introduced to the reader here.Additional material and links are available at: http://www.requirementsengineering.info

Requirements Engineering

Selection of industrial arc welding robot with TOPSIS and Entropy MCDM techniques

Study on the mechanical properties of the nanoconcrete using nano-TiO2 and nanoclay

This paper’s persistence is to make an inclusive analysis of 268 documents about specific energy consumption (SEC) in machining operations from 2001 to 2020 in the Scopus database. A systematic approach collects information on SEC documents’ primary data; their types, publications, citations, and predictions are presented. The VOSviewer 1.1.16 and Biblioshiny 2.0 software are used for visualization analysis to show the progress standing of SEC publications. The selection criteria of documents are set for citation analysis. The ranks are assigned to the most prolific and dominant authors, sources, articles, countries, and organizations based on the total citations, number of documents, average total citation, and total link strength. The author-keywords, index-keywords, and text data content analysis has been conducted to find the hotspots and progress trend in SEC in machining operations. The most prolific and dominant article, source, author, organization, and country are Anderson et al. “Laser-assisted machining of Inconel 718 with an economic analysis”, the Int J Mach Tools Manuf, Shin Y.C., form Purdue University Singapore, and United States, respectively, based on total citations as per defined criteria. The author keywords “specific cutting energy” and “surface roughness” dominate the machining operations SEC. SEC’s implication in machining operations review and bibliometric analysis is to deliver an inclusive perception for the scholars working in this field. It is the primary paper that utilizes bibliometric research to analyze the SEC in machining operations publications expansively. It is valuable for scholars to grasp the hotspots in this field in time and help the researchers in the SEC exploration arena rapidly comprehend the expansion status and trend.

https://www.mdpi.com/2071-1050/13/10/5617/pdf

Bibliometric Analysis of Specific Energy Consumption (SEC) in Machining Operations: A Sustainable Response

An effort is made in this work to appraise the surface characteristics of machined expandable polystyrene (EPS) with a novel 3D printed thermoplastic acrylonitrile-butadiene-styrene (ABS) tool. Linear grooves on EPS were made on a vertical milling machine that was modified to conduct experiments in the laboratory. The tests were designed as per the Taguchi L9 based factorial design of experimentation while varying process parameters such as depth of cut, spindle speed, and feed rate. The machining responses dimensional accuracy and surface roughness of the machined grooves were studied. Furthermore, the surface topography of the machined specimens was considered to investigate the mechanism of material removal in response to the processing conditions. Moreover, mathematical models developed for the prediction of the output responses showed a significant correlation with the experimental results. The results of the statistical study indicate that the surface roughness is influenced by the spindle speed and dimensional accuracy by the depth-of-cut. Overall, the findings of the experimental work advocated the feasibility of 3D printed thermoplastic tools for machining soft polymeric materials. It can become a useful alternative for mass and batch production.

Surface Characteristics of Machined Polystyrene with 3D Printed Thermoplastic Tool

Analysis of angular shrinkage of fused filament fabricated poly-lactic-acid prints and its relationship with other process parameters

Investigating the optimum parametric setting for MRR of expandable polystyrene machined with 3D printed end mill tool

Rapid prototyping technology (RPT) is a new class of manufacturing process in which part is being made with layer-by-layer deposition of the work material In this work, an effort has been made to study the tensile strength of polylactic acid (PLA)-based fused filament fabricated parts under the response of different input parameters (such as built orientation, head speed, and layer thickness) The experimentation has been conducted as per Taguchi L9 orthogonal array and a total of 9 × 3 samples have been prepared by using an open-source fused filament fabrication (FFF) setup Finally, the obtained data were investigated, statistically, in order to find out the significance of selected process variables on tested samples It has been observed that the build orientation has significantly influenced the obtained tensile strength of the PLA parts at 95% confidence level Whereas the process parameters, such as layer thickness and head scan speed, have remained un-influencing and it was observed from the Taguchi analysis that the orientation has a major effect on the strength of specimen printed by PLA analysis Whereas head speed and layer thickness had a least impact

Some Investigations on the Tensile Strength of Additively Manufactured Polylactic Acid Components

Inkjet printing (IJP) is a more demanded and preferable three-dimensional printing technology in the market, as it provides cost-effective solutions to biomedical, bioelectronics, pharmaceutical, and other applications. In the current scenario, researchers are promoting the combination of IJP and nanomaterial for developing efficient, smart, and functionally enabled products. However, this technology faced many problems, including weak durability, clogging, ink bleeding, inability to print high volume, and dimensional inaccuracies. In this chapter, an attempt has been made to feature the recent research insights into nanomaterials, the preparation of bioinks, and IJP. Further, the application of the nanomaterial driven IJP for tissue engineering, artificial organs, artificial skin, and bioelectronics has been dealt. This book chapter will be an invaluable source of knowledge to researchers, academia, and industry experts developing new innovative nanomaterials to produce low-cost biomedical products.

Kamalpreet Sandhu

Papers

Surface Characteristics of Machined Polystyrene with 3D Printed Thermoplastic Tool

Analysis of angular shrinkage of fused filament fabricated poly-lactic-acid prints and its relationship with other process parameters

Investigating the optimum parametric setting for MRR of expandable polystyrene machined with 3D printed end mill tool

Some Investigations on the Tensile Strength of Additively Manufactured Polylactic Acid Components

3D printing of nanomaterials using inkjet printing