This design study aims to reduce the discomfort and facial trauma seen with the use of the MBU-20/P oxygen mask for fighter pilots of the Royal Netherlands Air Force. To achieve this, the following research questions are answered:
•Are the reported issues with F-16 pilot oxygen mask usage still present with current F-35 fighter pilots?
•Are there differences in facial features between Dutch and American fighter pilots and does this influence the fit?
•Is it possible to design a better fitting mask with digital fabrication tools?
The current shape of the oxygen mask is based on anthropometric research on American male fighter pilots from 1967. Since the introduction of the current oxygen mask used by the Royal Netherlands Air Force in the 1990’s, the design has not changed. No anthropometric research has been conducted on how this mask shape fits European or Dutch male and female pilots. To answer the research questions, various methods were used. Semi-structured interviews and questionnaires were conducted with F-35 pilots to identify their issues. Anthropometric research was conducted to analyze facial differences in Dutch and American fighter pilots. A virtual fit analysis algorithm was created to better understand the relationship between mask shape, facial features and discomfort. Based on these analyses a new oxygen mask design was proposed using digital fabrication techniques and the design was evaluated in flight like conditions. The results of the study showed that current F-35 pilots still experience discomfort and, in some cases, facial trauma from using the oxygen mask. The greatest discomfort was experienced on the nasal root, which is in line with literature. High G-forces and prolonged time of wearing the mask increased this discomfort, leading to adverse behavior and possible unsafe situations. Significant differences in facial features were found between Dutch fighter pilots and the American fighter pilots, on which the design is based. The current sizing system of the oxygen mask does not cover the Dutch fighter pilot population properly. The differences facial features and improper sizing system were considered to be a main contributor of the discomfort experienced by Dutch fighter pilots. The virtual fit analysis showed how the current design’s shape does not fit the facial features of Dutch fighter pilots well. By considering the pressure discomfort threshold and soft tissue thickness, better insights were generated on the fit and associated discomfort of oxygen masks. The virtual fit analysis was used together with a parametric model to quickly and iteratively redesign the oxygen mask, based on anthropometric data. These models enabled the creation of redesigns which are better suited for the facial features of Dutch fighter pilots. The redesign was evaluated through physical evaluation, production cost estimation and a reflection on requirements and wishes. The physical evaluation showed a significant decrease in pressure at the nasal root, an overall reduced pressure on the face, an improved pressure distribution and increased comfort of the redesign...

This research provides a recommendation for Sonion, a company specialised in the development and production of hearing aids, on the production of moulds for the injection moulding machine.

The goal was to develop a process that reduces the cost and the time to manufacture an injection mould while maintaining a similar accuracy as in conventional mould production. Usually, Sonion outsources the production of injected moulded parts, resulting in parts with a tolerance of ~ ±10 µm that cost €15.000 for a 1000 pieces with a delivery time of 6-8 weeks. For Sonion’s development process, which is prototype heavy, this is too expensive and takes too much time. A micro injection moulding machine is acquired to shorten the iteration time of their design process and to reduce cost.

Before and during this research, the possibilities of 3D printing the moulds with a thermal resistant resin were being explored. For that reason, 3D printing with these materials was left out of the scope of this project. Although the accuracy for this method is sufficient, it struggles with the high pressure and temperature it is exposed to while injection moulding.

After identifying many possible manufacturing methods, the most promising techniques capable of withstanding the injection moulding temperature were chosen and validated through testing, research and consulting experts. For a total of six methods, the physical performance (a combination of accuracy, surface roughness and tool life) and the feasibility (iteration time, cost, form freedom and ease of execution) was determined. From the selected six methods, two were recommended for further exploration and investigation; Micro Metal Casting and Powder Injection Moulding. The other methods fell short due to a lack of accuracy, causing iteration time to be too long and the inability to manufacture certain parts of the mould.

The Micro Casting method works on the principle of the lost wax casting and is taken to a higher level by increasing its ability to replicate a shape. Both fully outsourcing the production and in-house production have been tested with similar results; the in-house production being slightly more accurate with a lower surface roughness. Metal moulds can be produced with a tolerance of ±25 µm for a price of around €750 within one to two weeks. It is recommended that for the continuation of this method, first the already acquired moulds are tested and future designs are fully outsourced until higher accuracy and lower surface roughness are required.

Powder Injection Moulding is a method capable of moulding metal parts at a temperature of 190 °C by mixing a fine metal grain with a polymeric binder and therefore could be used to produce a metal injection mould. In theory, the 3D printed moulds should be able to resist this temperature since it is relatively low. After moulding, the part goes into the oven for the polymer to debind and the grains to be sintered together.
A collaboration with the Powder Injection Moulding company Demcon had been setup for testing, but due to misaligning agendas it could not be set in motion. A test with a similar material has been conducted with highly detailed results. It is suggested to explore the possibilities of this method further.

In the Netherlands roughly 20.000 people wear an ocular prosthetic as a consequence of losing their eye due to an accident or disease. An ocular prosthetic is a type of facial prosthesis that replaces an absent natural eye. The main goal of an ocular prosthetic is to provide an aesthetic replacement of a real eye. It does not restore the ability to see. During surgery the eye is removed and a empty socket is left. An ocular prosthetic is custom made to fit that socket.

These prosthetic eyes are made by highly-skilled professionals who are called ocularists. They do this through a labour-intensive manual production process. This process consists of several steps such as obtaining the shape of the empty socket, consulting with patients and painting a realistic iris, sclera and pupil by hand. Traditionally these prosthetics are made with an acrylate called PMMA using a series of plaster moulds.

However the industry is moving towards digital production. The starting point for this thesis was an article written in 2021 by a research team from the Amsterdam Medical Centre consisting of Annabel L.W. Groot, Jelmer S. Remmers, and Dyonne T. Hartong. This article featured a proof-of-concept of a fully coloured 3D-printed ocular prosthetic. This showed that creating an realistic prosthetic using 3D-printing is possible. The next steps are integrating this knowledge into the daily work of an ocularist.

The goal of this thesis was to develop a new workflow for an ocularist in order to create an ocular prosthetic suited for 3D-printing by using computer aided design. To increase the efficiency of production and to help the ocularist with digitalization a custom tool was developed in the form of a parametric model. This parametric model is able to automatically generate 3D-geometry of an ocular prosthetic using 3D-scans of ocular impressions or digital reference models. By inputting manual measurements, photographs and parameters the ocularist is able to create eyes which offer a personalized fit for every patient. Five ocular prosthetics have been made using the new workflow and parametric model. These were then validated by comparing the results with prosthetics who are made using the same input but with the traditional method. The 3D-prints showed great promise for a new fully digital way of creating ocular prosthetics having low surface deviations with the original prosthetics .

The next steps are testing with real patients and further developing the parametric model into a dedicated software tool for ocularists.

Most ocularists seem to be far away from producing fully 3D-printed prosthetics for customers but this thesis is a good first step in the digitalization of the ocularist practice.

Transcended manufacturing is a new emerging manufacturing paradigm in response to the rising need for mass personalisation and ultra-personalised products. Through product personalisation, people can assert their identity in an increasingly impersonal world. But the one-off a kind nature of ultra-personalised make them hard to manufacture with traditional fabrication methods. Transcended manufacturing uses automation and digital manufacturing to manufacture ultra-personalised products. Hybrid fabrication is a digital manufacturing technique that combines multiple processes to provide new process capabilities. Hybrid manufacturing is still underdeveloped but could improve the field of personalised products and transcended manufacturing with its versatility and flexibility.

The project goal was to research hybrid fabrication and find and develop opportunities that may benefit Transcended manufacturing and ultra-personalised products.

The project started with an analysis of the current situation of digital manufacturing and the industry. The study resulted in multiple opportunities for hybrid fabrication and transcended manufacturing, from new processes that can be used for personalised product fabrication, to versatile and flexible manufacturing.

With the opportunities of hybrid fabrication defined, a future vision, a production scenario and exemplary product are created. These scenarios are used to ideate, conceptualise and develop a hybrid fabrication workstation. The future of hybrid fabrication looks bright but early adoption of hybrid manufacturing is in product research and development.

The workstation is further embodied and a prototype is created to showcase and kickstart hybrid fabrication and personalised product development. The prototype addresses reconfigurability and flexibility in hybrid systems and provides a platform and framework for hybrid manufacturing.

The future of hybrid manufacturing and transcended manufacturing looks promising. As the industry 4.0 grows and transcended manufacturing and hybrid fabrication mature, the new way of manufacturing ultra-personalised products can include hybrid fabrication systems.