Additive Manufacturing
Lead Research Organisation:
University of Sheffield
Department Name: Mechanical Engineering
Abstract
Additive Manufacturing (commonly known as 3D Printing) is the term used to describe a family of processing techniques that produce parts layer by layer as dictated by a three-dimensional computer model. Despite dramatic development of this field in recent years, there are a number of key issues to be addressed before it can become more widely adopted. Amongst the most critical of these is the need to develop the range of materials available for use in additive manufacture, thus expanding its applicability to further areas.
Laser Sintering and High Speed Sintering are two polymer-based processes that have been extensively researched in the Centre for Advanced Additive Manufacturing at Sheffield, showing particularly exciting potential for industrial use. In particular, these processes offer the possibility of including specific filler materials to provide an increased range of part properties. These have traditionally tended to focus upon improvements to mechanical properties, but have the potential to provide additional functionality (e.g. temperature performance, biological properties or even scent/colour). This project will focus on addressing the increasing concern over Anti-Microbial Resistance (AMR) by incorporating anti-bacterial properties into a part at the manufacturing stage.
Aim
The overall aim of this project is to provide increased functionality for powdered - polymer AM processes through inclusion of specialised filler materials.
Objectives
Specific objectives include:
1) Determination of most high-impact functionality requirement
2) Identification of potential methods to achieve this increase in functionality
3) Screening of methods identified in 2)
4) Full-scale characterisation of most promising method
5) Dissemination and identification of collaborative opportunities'
Laser Sintering and High Speed Sintering are two polymer-based processes that have been extensively researched in the Centre for Advanced Additive Manufacturing at Sheffield, showing particularly exciting potential for industrial use. In particular, these processes offer the possibility of including specific filler materials to provide an increased range of part properties. These have traditionally tended to focus upon improvements to mechanical properties, but have the potential to provide additional functionality (e.g. temperature performance, biological properties or even scent/colour). This project will focus on addressing the increasing concern over Anti-Microbial Resistance (AMR) by incorporating anti-bacterial properties into a part at the manufacturing stage.
Aim
The overall aim of this project is to provide increased functionality for powdered - polymer AM processes through inclusion of specialised filler materials.
Objectives
Specific objectives include:
1) Determination of most high-impact functionality requirement
2) Identification of potential methods to achieve this increase in functionality
3) Screening of methods identified in 2)
4) Full-scale characterisation of most promising method
5) Dissemination and identification of collaborative opportunities'
Organisations
People |
ORCID iD |
| Candice Majewski (Primary Supervisor) | |
| James Wingham (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509735/1 | 01/10/2016 | 30/09/2021 | |||
| 1949272 | Studentship | EP/N509735/1 | 01/10/2017 | 18/08/2021 | James Wingham |
| Description | This research has focused on adding functionality into laser sintered (3D printed) parts. This has centred around creating antibacterial parts through the use of silver-containing additives, with the resulting parts proving effective against different strains of bacteria (including well known "superbugs" such as MRSA). These findings have been published in a high impact journal. During this work, additional research into novel methods of non-destructive testing have been used. The use of micro-CT to quantitatively observe the additive distribution inside printed parts has been investigated, with the results shown in a journal publication. |
| Exploitation Route | This method of adding functionality to laser sintered parts can be applied to a variety of different properties. Specifically relating to antibacterial properties, there are numerous additives which could have an antibacterial effect and could be researched. The use of micro-CT to analyse part microstructure might not lead directly onto further research; however, this could be a useful tool in a wide variety of studies. |
| Sectors | Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology |
| Description | Additive Manufacturing - 6-Month Covid-19 Extension |
| Amount | £9,000 (GBP) |
| Organisation | United Kingdom Research and Innovation |
| Sector | Public |
| Country | United Kingdom |
| Start | 02/2021 |
| End | 08/2021 |
| Description | Postgraduate Research Student Publication Scholarship |
| Amount | £3,902 (GBP) |
| Organisation | University of Sheffield |
| Sector | Academic/University |
| Country | United Kingdom |
| Start | 01/2022 |
| End | 04/2022 |
| Title | Data Relating to "Micro-CT for analysis of laser sintered micro-composites" |
| Description | This contains all of the data presented in: J.R Wingham et al., "Micro-CT for analysis of laser sintered micro-composites," Rapid Prototyping Journal, 2020. [Online]. Available: https://doi.org/10.1108/RPJ-08-2019-0211 All information regarding this data is included in the above publication, which must be referenced in full if using this data. Access to this data can be requested from the corresponding author (James Wingham - jrwingham1@sheffield.ac.uk) or by contacting Candice Majewski (c.majewski@sheffield.ac.uk). Abstract: X-Ray Computed Micro-Tomography (Micro-CT) is relatively well established in Additive Manufacturing as a method to determine the porosity and geometry of printed parts, and in some cases the presence of inclusions or contamination. This paper demonstrates that micro-CT can be also be used to quantitatively analyse the homogeneity of micro-composite parts, in this case created using Laser Sintering (LS). LS specimens were manufactured in polyamide 12, with and without incorporation of a silver phosphate glass additive in different sizes. The specimens were scanned using micro-CT to characterise both their porosity and the homogeneity of dispersion of the additive throughout the volume. This work showed that it was possible to use micro-CT to determine information related to both porosity and additive dispersion from the same scan. Analysis of the pores revealed the overall porosity of the printed parts, with linear elastic fracture mechanics used to identify any pores likely to lead to premature failure of the parts. Analysis of the additive was found to be possible above a certain size of particle, with the size distribution used to identify any agglomeration of the silver phosphate glass. The particle positions were also used to determine the complete spatial randomness of the additive as a quantitative measure of the dispersion. This shows that micro-CT is an effective method of identifying both porosity and additive agglomeration within printed parts, meaning it can be used for quality control of micro-composites and to validate the homogeneity of the polymer/additive mixture prior to printing. This is believed to be the first instance of micro-CT being used to identify and analyse the distribution of an additive within a Laser Sintered part. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2020 |
| Provided To Others? | Yes |
| Impact | Supporting data for a journal publication, no notable impact(s). |
| Title | Data relating to "Use of silver-based additives for the development of antibacterial functionality in Laser Sintered polyamide 12 parts" |
| Description | This contains all of the data presented in: R. Turner et al., "Use of silver-based additives for the development of antibacterial functionality in Laser Sintered polyamide 12 parts," Scientific Reports, vol. 10, p. 892, 2020. [Online]. Available: https://doi.org/10.1038/s41598-020-57686-4 All information regarding this data is included in the above publication, which must be referenced in full if using this data. Corresponding authors: Joanna Shepherd (j.shepherd@sheffield.ac.uk) and Candice Majewski (c.majewski@sheffield.ac.uk). Abstract: Infectious diseases (exacerbated by antimicrobial resistance) cause death, loss of quality of life and economic burden globally. Materials with inherent antimicrobial properties offer the potential to reduce the spread of infection through transfer via surfaces or solutions, or to directly reduce microbial numbers in a host if used as implants. Additive Manufacturing (AM) techniques offer shorter supply chains, faster delivery, mass customisation and reduced unit costs, as well as highly complicated part geometries which are potentially harder to clean and sterilise. Here, we present a new approach to introducing antibacterial properties into AM, using Laser Sintering, by combining antimicrobial and base polymer powders prior to processing. We demonstrate that the mechanical properties of the resultant composite parts are similar to standard polymer parts and reveal the mode of the antibacterial activity. We show that antibacterial activity is modulated by the presence of obstructing compounds in different experimental media, which will inform appropriate use cases. We show that the material is not toxic to mammalian cells. This material could be quickly used for commercial products, and our approach could be adopted more generally to add new functionality to Laser Sintered parts. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2020 |
| Provided To Others? | Yes |
| Impact | Data supporting a journal publication, no notable impact(s). |
| Description | Case study article |
| Form Of Engagement Activity | A magazine, newsletter or online publication |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Schools |
| Results and Impact | I was invited to write an article for Create Education, summarising the research from this work for their more general audience. |
| Year(s) Of Engagement Activity | 2021 |
| URL | https://www.wevolver.com/article/introducing-antibacterial-properties-into-additive-manufactured-par... |