The lack of a rigid backbone gives the arms of the octopus potentially infinite degrees of freedom, which makes them highly flexible and hyper-redundant. This would require a high level of computing resources if the body morphology of these arms would not have been designed so that their interaction with the environment simplifies their actuation. Their body morphology encodes strategies to translate a simple input into complex movements, e.g. to reach and fetch prey. Encoding these strategies in the design of artificial soft bodies can simplify the actuation of complex movements in soft robotic applications and extend soft robotic functionalities. Manufacturing techniques should be developed to incorporate this kind of intelligence in artificial soft bodies mechanically.

This study focuses on the working principles behind the embodied intelligence of the octopus arm and the development of manufacturing techniques to acquire the same level of mechanical intelligence in artificial soft bodies. Smart materials will be combined with conventional and unconventional silicone manufacturing techniques. Comparable to the octopus arm, these intelligent soft bodies are functional in small- and large-scale applications, which makes them widely employable. Examples of applications that could benefit from these intelligent soft bodies are steerable catheters for Minimal Invasive Surgery or soft grippers for deep-sea exploration.

For more information, please contact Vera Kortman, v.g.kortman@tudelft.nl

Photo by Oleksandr Sushko on Unsplash

A Bio-inspired Suction Cup for Vacuum Delivery (CLOSED)

Vacuum-assisted delivery is a medical procedure in which a vacuum device is used to guide the baby through the birth canal, when problems arise during the delivery. This device makes use of a hard plastic suction cup that is attached to the baby’s head. Excessive suction forces cause a cone-shaped swelling on the baby’s head, which increases the risk of bruising, bleeding in the skull and skull fracture.

In this graduation project, you will explore a 3D printed variable stiffness suction cup that can adapt to the shape of the baby’s head. You will be taking inspiration from animals with suction cups, such as the octopus, as those can perfectly adapt their discs to the objects they grasp. We want to use the form complexity of 3D printing to create the suction cup. This is an exploratory assignment, so we are looking for a creative student with an investigative, curious mind and experience with Solidworks.

Interested? Contact Vera Kortman (v.g.kortman@tudelft.nl) or Kirsten Lussenburg (k.m.lussenburg@tudelft.nl).


[image courtesy of EOS]

CloudWalker, towards accessible low-effort exoskeleton walking

This research project is funded by Care for Quality of Life Foundation.

A spinal cord injury is an uncommon but serious condition. In addition to paralysis symptoms, people with a spinal cord injury have many additional health problems, such as pain, spasticity and sore spots. A spinal cord injury therefore causes significant obstacles to social participation and a lower quality of life. In addition, wheelchair users with a spinal cord injury are physically inactive, which leads to new health problems, such as sore spots and cardiovascular disease. Regular exercise is therefore very important to stay in good health. Walking in an exoskeleton even offers health benefits, including reduced spasticity and improved intestinal function. People also find standing interaction valuable and experience an improved quality of life. To maintain these benefits, regular use of an exoskeleton is necessary.

However, the commercially available motorized exoskeletons are difficult to handle, heavy and have little added value in daily life. In addition, they are very expensive. This makes walking exercise only accessible to a small group of people. In this project we are developing a safe, user-friendly, lightweight and affordable exoskeleton, with which we can make walking possible for a much larger proportion of people with leg problems. Characteristic of this exoskeleton is that the user can drive it efficiently with his own body force from the upper body. The first developed prototype contains hinged hips that are connected to each other via a flexible coupling. Movement of the upper body allows the user to move one leg forward. Energy is stored in the elastic element with each step, which is released again in the next step.

Nianlei Zhang is currently working on this project as his Ph.D. research. Are you interested?

Relevant links:
Cloudwalker: werktuigkundige principes en menselijk functioneren komen samen
The Cloud Walker: a lightweight, user-driven exoskeleton for people with Spinal Cord Injuries

Computational design optimization of patient-specific shape-morphing catheter tips

This research project is funded by the faculty of Mechanical Engineering of Delft University of Technology.

Catheters are essential for minimally invasive procedures to diagnose and treat pathologies such as heart failure. The vascular system exhibits a complex geometry with multiple branches, junctions and obstacles. Selection of the appropriate tools and shapes requires thorough planning and patient imaging data. To ease the procedure and limit the consecutive use of catheters with different tip shapes, there is a need for versatile compliant tips that can smoothly morph between patient-specific predefined shapes.

This research aims to develop a computational optimization framework to design wire-actuated compliant catheter tips that deform between predefined shapes as a function of the magnitude of force applied by the operator. The framework allows for designing tips with variable tube wall geometry, material properties, and wire guiding patterns while preserving the tube-like structure of the tip. Collectively, these variables allow for the design freedom required to achieve tailored local mechanical properties and loading that jointly define extreme shape-morphing capabilities.

Plant root inspired steerable needle for urology (CLOSED)

This graduation assignment focuses on the design of a steerable needle for urology procedures, in specific prostate cancer treatment, with a focus on improving accuracy, precision, and patient comfort. The design of the needle will be inspired by the root system of plants, particularly how they extend and move through soil. The tip of the needle will have an extension that can be steered to the desired location within the prostate. 

The assignment involves designing, developing, and testing a novel steerable needle that allows for accurate needle positioning. We are looking for a student who is interested in a design-oriented project and who can start at short notice (i.e., spring or summer 2023). For this project, creative problem solving, SolidWorks, and 3D-printing skills, and an interest in medical topics would be useful. 

Interested? Please contact Jette Bloemberg, j.bloemberg@tudelft.nl, and/or Esther de Kater, e.p.dekater@tudelft.nl.

Design an adjustable medical cast

When a patient has a broken bone often a customized medical cast is made to immobilize that part of the body where the broken bone is located in order for the bone to heel. Every patient receives a custom made cast or a custom made splint. The cast is made by specialist in the hospital. During the heeling of the bone patients suffer from muscle atrophy because of the immobilization. This occurs typically after 5 days of immobilization. This can cause more space between the cast and part of the body of the patient where the cast is located. This can reduce the function of the cast. On the other hand is some mobilization helpful for the healing process.

In this graduation project, you will design an adjustable medical cast so that the immobilization is optimized and the muscle atrophy minimized.

Interested? Contact Karin Thomassen k.e.thomassen@tudelft

Monitoring medical cast

When a patient has a broken bone often a customized cast is made to immobilize that part of the body where the broken bone is located in order for the bone to heel. Every patient receives a custom made cast or a custom made splint. During the phase of immobilization most patients are not hospitalized. Therefor their physician cannot monitor the heeling process of the bone. What noninvasive device could help both patient and physician to get a better insight in the heeling progress during immobilization in order to minimize the immobilization phase so that complications like muscle atrophy is minimalized?

In this graduation project, you will design a non-invasive monitoring medical cast to inform both patient and physician about the progress of the healing of the bone.

Interested? Contact Karin Thomassen k.e.thomassen@tudelft

Ovipositor MRI-Needle

Developed in 2020-2021, diameter 0.8 mm.

Female parasitic wasps pass their eggs through an organ called the ovipositor into their hosts, which sometimes hide in a solid substrate such as wood. The ovipositor has the shape of a tube and consists of three slender, parallel-positioned segments, called valves. The wasp can push and pull the valves with respect to each other in a reciprocating manner. A groove-and-tongue mechanism interlocks the valves along their length. The push-pull motion of the valves has two functions. First, it keeps the unsupported length of the individual valves low. Second, moving the individual valves forward one by one while pulling the others provides stability to the wasp’s ovipositor and prevents buckling. The push and pull forces produce a net force near zero, enabling a self-propelled motion.

Inspired by the wasp ovipositor, we developed a self-propelled Ovipositor MRI-Needle with a diameter of 0.8 mm that can be used inside an MRI system. Our needle consists of six parallel needle segments and an actuation unit. The design of the actuation unit is based on the so-called click-pen mechanism of a ballpoint pen. The actuation unit allows you to actuate the needle that consists of six parallel Nitinol segments by just a translating motion. We 3D-printed the components of this actuation to be able to test it inside an MRI system. The video below shows the movement of the needle segments actuated by the actuation unit:

The prototype was tested with success in ex-vivo human prostate tissue in a preclinical 7-Tesla MRI system at the Amsterdam University Medical Centres. The results showed that the needle tip was visible in MR images and that the needle was able to self-propel through tissue.

This project, in which we developed a self-propelled wasp-inspired needle that can be used inside an MRI system, is part of Project 4 of the MEDPHOT programme funded by the Netherlands Organization for Scientific Research (NWO). MEDPHOT focusses on the development of photonics-based technologies that can enable earlier diagnosis and tailored treatment of diseases in the pulmonology, urology, and gastroenterology fields and translate these technologies to their clinical environments. The goal of Project 4 is to develop a novel transperineal laser ablation platform for an accurate treatment of prostate tumours under MRI.


Spinal bone anchor fixation by molding to the pedicle (CLOSED)

During spinal fusion surgery, multiple vertebrae are fused by fixating them together. The fixation of the vertebrae is achieved by placing screws through the pedicles of the vertebrae that are connected to rods. The fixation strength of the screw mainly relies on the contact area between the screw and the outer bone layer of the vertebra. This contact can only be achieved within the pedicle of the vertebra. However, even in the pedicle, this contact is limited due to the hourglass shape and oval cross-section of the pedicle.

In this graduation project, you will design a bone anchor that can adapt its shape in 3D to the pedicle of the vertebra to fixate to increase the contact area between the anchor and the cortical outer layer of the pedicle.

Interested? Contact Esther de Kater, E.P.dekater@tudelft.nl

Design of an internal fixation system for spinal fusion surgery (CLOSED)

During spinal fusion surgery multiple vertebrae are fused by fixating them together. The fixation of the vertebrae is achieved by placing screws through the pedicles of the vertebrae that are connected to rods. The rods run along the vertebrae and are embedded in the surrounding soft tissue. This can result in pain and irritation for the patient.

The vertebra grow together and form one bony mass in the first six months after surgery. During this period the forces acting on the fixation are substantial during daily activities. If the screw loosen during this period, the desired fusion cannot be achieved.

In this graduation project we will set the first steps in the direction of a new fixation method that is mainly located within the vertebra. The graduation projects focuses on the development of a drilling and/or anchoring system that can be used to create the desired fixation.

Interested? Contact Esther de Kater, E.P.dekater@tudelft.nl

Solving medical problems through nature’s ingenuity