WHICH 3D PRINTED STRUCTURE IS MOST CELL FRIENDLY?

Orthopedics This Week (OTW) has reported on our study of topology to improve osteogenesis in load-bearing implants.

They interviewed us and quoted this extract from that interview as follows:

Dr. Torres-Sanchez told OTW, “Although we are all different in terms of anatomy and physiological needs …in the ways we age, exercise, and live, medicine/technology that feeds into medical devices has largely been a one-size-fits-all approach. My 82-year-old neighbor has a very different lifestyle different from my 57-year-old neighbor who bikes 10 miles a day. If both individuals are in an accident and need an orthopedic device, they will need different products. With personalized medicine we have improved chances of producing long lasting orthopedic devices that allow cells to move in and create a mineral material that makes up our bone and carries no risk for infection.”

https://ryortho.com/breaking/which-3d-printed-structure-is-most-cell-friendly/

The full interview can be read here.

The study that this interview is referring to can be found here. The sponsors are EPSRC/UKRI and our inductrial partners are Alloyed Ltd and Core Specialist Services Ltd.

Magnetic Fields to Aid the Manufacturing of hi-performing Composites

Bradley Mee has spent his Wolfson bursary in our lab developing a novel method to align reinforcing fibres within a polymeric matrix using magnetic fields. In this way, the mechanical properties of the composites can be tailored for specific applications and load requirements.

In his final report he wrote:

“Polyurethane composites are widely used due to their strength and light weight-ness, as well as the low cost and scalability in production. The PU material comes in two separate liquid chemicals that once combined in equal amounts rapidly expand to 200% of the original volume and cure hard, taking the shape of the mould it is placed in. There is an opportunity to shape and further increase the strength of these parts by forming a composite of PU and carbon fibres (added in the liquid/expanding stage), with localised reinforcements. It has previously been shown that these composite materials produced increase stiffness in both tensile and compressive testing.

The aim of the project is to test the hypothesis that [a magnetic field] aids the alignment of carbon fibres in a certain direction and will increase the strength of the material, compared to randomly located fibres. To achieve this; firstly, a literature review of electromagnetism and permanent magnets was carried out. Secondly, finite-element software was used in order to create a model of the problem and to visualise the magnetic fields created by the magnets. These two objectives provided the basis for a prediction on the direction and alignment that magnetised carbon fibres. Thirdly, lab-based experiments were carried out using a magnetometer to measure the actual magnetic field strength in air. The results were compared to those of the computer model and confirmed to be congruent. Finally, composites were produced in a bespoke mould and the specimens underwent mechanical testing.”

Bradley in the lab during sample production

Bradley has returned to his Electrical and Electronics Engineering studies and is aiming to pursue a career in the aerospace where these high performing composites could be in use in the near future.

Enhanced mechanical performance of lightweight polyurethane foam reinforced with a low content of aligned magnetised short carbon fibres

Our latest work for the manufacture of reinforced cellular polymeric structures is out now. We used a hybrid manufacturing process using insitu magnetisation of carbon fibres that then could be guided, oriented and positioned to those areas of the reacting polymeric core where reinforcement was most needed. In this study we found out that:

• It is possible to attach magnetite nanoparticles to carbon fibres via a facile electrochemistry route, quick and suitable for mass production
• These magnetised fibres can be aligned in a structural foam such as a rigid thermoset (polyurethane) foam using a relatively weak source magnetic field
• The tensile mechanical properties are improved with content loading as low as <0.4%vol, making this approach economic for the manufacturing industry of lightweight composites.

The paper can be accessed at the Composite Interfaces Journal via Taylor & Francis Online.

For a full description of the work and sponsoring bodies, visit this page.