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 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.

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’.

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.