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.

An ankle-foot orthosis (AFO) is a medical aid that helps individuals with deficient walking patterns achieve a more natural gait. There are various types of AFOs prescribed for different reasons. This thesis specifically focuses on passive dynamic ankle-foot orthoses (PD-AFOs) and even within that branch a very specific type: the carbon dorsal leaf spring orthosis. This type of AFO leverages the body’s biomechanics and gravitational forces to store and release energy at precise phases of the gait pattern, helping to restore some of the ankle function. Furthermore, they address the issue of excessive plantar flexion during the swing phase of gait, which can result in foot drop or an undesirable foot-slamming motion.

To ensure optimal fit and functionality, these orthoses are custom-made to provide the best fit for the lower leg and foot of each individual. Currently, the manufacturing process for these orthoses involves labour-intensive carbon composite layering techniques, which require significant effort and expertise.

An alternative AFO concept was designed, which aims to replicate the behaviour of existing carbon dorsal leaf spring orthoses using SLS-3D printing. This direction was explored as additive manufacturing excels in one-off production and eliminates the need for manual labour, offering cost-effective and efficient production of personalized items. This case is therefore carried out for the companies Parts on Demand, a selective laser sintering (SLS) 3D-printing company, and Livit Ottobock Care, an orthopedics company, to further investigate the feasibility of such an orthosis.

This study involved multiple design iterations, primarily focused on the stiffness behaviour of the AFO to create a novel SLS printable design that exhibits similar stiffness characteristics and gait influence compared to the existing carbon dorsal leaf spring AFOs produced by Livit Ottobock Care, whilst maintaining comparable weight and cost.

A model was created to parametrically refine SLS printable AFOs based on scanned lower leg and foot data for repeatable results using different feet. Subsequently, prototypes were fabricated using this model to validate the quantitative stiffness behaviour and qualitative correction of user gait resulting in an orthosis with a comparable function to the baseline carbon dorsal leaf spring orthosis.

Initial results seem promising for the feasibility of SLS printing PD-AFOs, but requires further validation, as many aspects related to their longevity were excluded from this study. These factors include its fracture resistance over longer periods of time, whether stiffness fatigue will occur, or how the AFO will behave mediolaterally. Nonetheless, producing an SLS-printed orthosis can provide benefits in the long run which for example include not only customized and well-fitting orthoses but also tailored stiffness characteristics for each individual, enhancing the function of the ankle and foot during walking. However, it is important to note that research in this area is currently insufficient.

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.

This master thesis explores multiple important aspects for the design of an osseointegrated bionic arm prosthesis such as customizability, modularity and aesthetics and can serve as a stepping stone in the development of this bionic arm prosthesis called ‘Ellis’.

In this report the development and design of Claus is presented. Claus is an auxiliary drive train module for last-mile delivery hand trucks. The objective of the concept is to enable delivery workers to deliver parcels to the growing amount of addresses in urban environments with limited mobility access.

Due to the combination of urbanization, the rising popularity of e-commerce and rising congestion levels in cities, delivery companies are increasingly struggling to transport their goods to the customer. Conventional delivery fleets, consisting of big delivery vans to handle the rising delivery volumes, are not suited to the urban environment anymore as cities are undergoing rising congestion rates and as automobiles are becoming a less prioritized mode of transport. Consequently, delivery workers have to cover larger distances from the van to the front door of the customer by foot. Usually, delivery workers use hand trucks to cover these last meters, but as these distances increase, walking the hand truck becomes a time consuming job.
Claus is proposed as a solution for this last leg of parcel delivery. Claus is an auxiliary module with a built in electric drive train that connects to any regular hand truck. By connecting Claus to a hand truck, a four-wheel vehicle is created that can transport a the delivery worker along with his or her cargo. The hand truck acts as both the cargo carrier as well as the steering device, while Claus acts as a standing deck and a drive train. Thanks to Claus’ geometry and volume, Claus can be transported in a conventional delivery van similarly to the hand truck. By bringing both a hand truck and Claus during delivery shifts, delivery workers are enabled to quickly and easily cover areas that are becoming less accessible to delivery vans.

Two prototypes were created that were used to validate the concept. A technical prototype acted as a means to validate the driving characteristics and the ergonomics. Furthermore, it was used to validate technical aspects such as the battery capacity and the drive train system. An aesthetic prototype was used to communicate the design to the stakeholders.

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.

This graduation report presents a new mold making approach for Royal
Delft. The traditional production trajectory starts with a positive model and
pouring plaster mold parts onto it one by one, producing a negative casting
mold for one shape. This new proposal takes the plaster mold parts as a
starting point, combining them into a modular system that can be modified
continuously in order to produce many variations of a shape without starting
from scratch for every new shape. The benefit of this approach is that
shapes such as plates, vases and boxes can be quickly tailored to individual
customers, changing elements, adding personal texts and creating custom
vector reliefs.

In this project, a tool is developed to improve long-distance collaboration on the production of composites for the aerospace industry. In a literature review, four main things were explored. The concept of Mental Models and Common Ground, the concept of bandwidth, the current state of VR and VR collaboration and the composites of ATG. This formed the theoretical basis for the project.
It became clear that there were two knowledge gaps. The first one being the composite production process and the second being what communication tools were currently used and why.
To gain insight into the production process, an immersion exercise was done in which the designer did the actual production process. This was then made it into a timeline and discussed with the composite team to ensure it was accurate. The main conclusion was to focus on the alignment process.
Ten interviews were done to determine the use of each communication tool. The results of these interviews were then clustered and made into charts and a write-up. This indicated that a traceable and high bandwidth tool did not exist yet which presents an opportunity for VR.
For the conceptualisation, a set of requirements were created based on the previous research. These requirements helped to create a concept direction. The concept direction is a Virtual reality tool that does two main things. First, it records sketches, objects and the engineers’ position and voice in 3D over time to capture Mental Models. Secondly, by organising those Mental Models in a clear project structure that makes the Mental Models traceable and findable in a persistent project.
An almost fully featured prototype of the concept was build using a method called RITE (Rapid Iterative Testing and Evaluation). This meant multiple iterations of the prototype were made and evaluated. The QUESI questionnaire was used to evaluate the performance of each iteration.
A between-group study was done to evaluate the prototype on its ability to transfer Mental Models. Participants were shown either a video or a written description of a process, which they were then asked to answer questions about, resulting in an individual score. Furthermore, they were asked about their perceived understanding of the domain before and after the immersion activity, as well as their opinion on the experience. A video of the prototype was used so the study could be done online. This was necessary to recruit participants.
With 24 participants the results came back mostly insignificant but the video of VR did perform better on clarity and experience. It performed slightly higher but not significantly so on the score and the perceived understanding. That is still a promising result as preparation time was lower and the VR tool is traceable.