Tribology & Biotribology

Tribology could be considered the most interdisciplinary subject known compared with other engineering or physical science disciplines. Overall, it is related to Mechanical Engineering, Materials Science Engineering, Chemistry, Physics, Mathematics, as well as Biology. Based on the Greek root “tribos”, meaning to rub, tribology is the study of surfaces that have relative motions. Tribological considerations, such as surface roughness, material compatibility, and contact stresses, should be noticed in the design, manufacture, and use of anything that is in contact with another object. The applications of tribology include individual components (gears, bearings, brakes, etc.), assemblies (engines, pocket watches, etc.), manufacturing processes (rolling, turning, grinding, stamping, etc.), construction (mine slurry pumps, oil drilling rig, excavator, etc.), and natural phenomena (water/wind erosion, plate tectonics, etc.). The commonality between these applications is that two different surfaces are in contact or have a relative motion. Two aspects of these surfaces, including physical (surface roughness) and chemical (intervening layers), should be taken into consideration due to their vital roles in tribology.

Overlapping key fields of study in Tribology

Tribology is mainly composed of three fields, namely friction, wear, and lubrication. These terms can be defined as follows:

Friction: Friction is the resistance to relative motion between two bodies in contact. There are two microscopic forces, called molecular adhesion and mechanical abrasion, between these two objects in touch. Molecular adhesion includes electrostatic, Van der Waals, as well as metallic bonds while mechanical abrasion comprises elastic, plastic, and viscoelastic deformations. Friction can be measured by the coefficient of friction which is a constant of proportionality.

Wear: Wear is the removal or displacement of material from one body when subjected to contact and relative motion with another body. Like friction, wear is a system property and not a material property. There are several distinct wear regimes, including abrasive wear, adhesive wear, fretting corrosion, erosive wear, rolling contact fatigue, and tribo-corrosion. Some of these regimes can operate simultaneously or sequentially. The wear rate significantly changes according to the wear mode which is a function of the Tribosystem.

Lubrication: Lubrication is the use of a fluid to minimize friction and wear. The critical roles of a lubricant are to reduce friction, prevent or minimize wear, transport debris away from the interface, and provide cooling. Different lubrication regimes, including boundary lubrication, mixed lubrication, and fluid film lubrication, are determined based on the fluid film thickness. These regimes are also described by the Stribeck curve.

The expression of “Biotribology” was first defined by Dowson in 1970, which considers all aspects of tribology associated with biological systems, particularly the synovial joints and joint replacements. Biotribology pertains to friction, wear, and lubrication at biological interfaces. Studying the biotribology of the natural synovial joints helps us to better understand the joints’ function as well as the development of related diseases, and to figure out what kind of medical interventions are required. This could contribute to enhancing the quality of life of patients suffering from diseases associated with synovial joints.

 

Learn more at Tribology 101 – Introduction to the Basics of Tribology | Dr. Arun Sikder, Bruker USA, 2019

 

This article was written by Mahdieh Mosayebias part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Mahdieh is researching the Design of Self Lubricating Prothesis at ETH Zurich, Switzerland.

Industrial secondment at SWERIM AB

Since August, Vidhiaza and Giulio have been going to SWERIM AB as part of their BioTrib secondment plans. SWERIM AB is an institute that conducts industrial research and metals development. They have a location in Stockholm, just an hour away by train from Uppsala. At SWERIM AB, Vidhiaza and Giulio conduct experiments with the powder that they use for additive manufacturing. This brings a lot of synergy to their research as Uppsala University does not have the instruments to perform powder research.

Below, Vidhiaza is pictured with a spreadability tester in the SWERIM AB powder lab. This equipment can mimic the movement of a powder recoater that exists in an additive manufacturing machine to produce a layer of powder. Vidhiaza and Giulio use this machine to check and predict if their powder will be readily spreadable during the AM process, i.e., the powder produces a nice, dense layer.

Here Giulio is pictured with a setup for powder flowability measurements. SWERIM AB powder lab has different set ups for powder flowability according to different standards. Flowability is also an exciting and relevant powder property to AM process because it is directly related to how well an AM machine can dispense the powder.


Overall, the secondment at SWERIM AB has been very educative for Vidhiaza and Giulio, and it definitely enriches their research experience as BioTrib ESRs!

 

This article was written by Giulio Cavaliere as part of a series articles curated by BioTrib’s Early Stage Researchers.

Giulio Cavaliere is investigating Additively manufactured biodegradable alloys for bone replacement at Uppsala University, Sweden.

 

 

 

This article was written by Vidhiaza Leviandhika as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Vidhiaza is researching the Development of Development of 3D-printed gradient alloys for joint implant component at Uppsala University, Sweden

Filippo Ganna breaks the hour record on a 3D printed Pinarello bike

Header Image: 3D Printed Pinarello Bolide F HR 3D bike [1].

The ultimate benchmark for a cyclist, 60 minutes alone in a velodrome, suffering and draining any drop of energy left in the body. It’s the Hour record, the longest distance cycled in an hour from a stationary position.

From 1876, when the American Frank Dodds rode 26.508 km on a penny-farthing, the hour record has been held by the greatest cyclists in history from Fausto Coppi to Eddy Merckx, from Francesco Moser to Bradley Wiggins.

But the record is not just an incredible demonstration of human strength and endurance, it’s also the place to test and develop new cutting-edge technologies. In 1984 Francesco Moser smashed the record established 12 years before by Eddy Merckx using a revolutionary bike with composite lenticular wheels and a very peculiar frame shape.

Rider on Pinarello Bolide F HR 3D Bike [1].
38 years later the hour record is once again Italian, Filippo Ganna cycled 56,792 Km in an hour in the Swiss velodrome of Grenchen. The bike he rode is almost as impressive as the record itself. The Pinarello Bolide F HR 3D was the first metal 3D-printed bike. The company used a high permeance aluminum alloy (scalalloy) 3D printed in an EOS M400, an industrial scale powder bed fusion (PBF) system. This was a proof of concept and used all the advantages of 3D printing over traditional manufacturing techniques. Firstly, the flexibility in design, the scale-like pattern on the seat tube greatly helps with the aerodynamic, but this is only obtainable through additive manufacturing. But also, fast prototyping allows customizing the frame to the need of any individual athlete without the need of realizing expensive and time-consuming mold for carbon fiber frames.

 

References

[1] “Bolide F HR 3D | En | Pinarello Global.” Accessed October 21, 2022. https://pinarello.com/global/en/bikes/road/competition/bolide-f-hr-3d/bolide-f-1.

 

This article was written by Giulio Cavaliere as part of a series articles curated by BioTrib’s Early Stage Researchers.

Giulio Cavaliere is investigating Additively manufactured biodegradable alloys for bone replacement at Uppsala University, Sweden.

Degradation of a metal-on-polyethylene (MoP) hip prosthesis: Preclinical outcomes

According to NJR (2021) report, UK continues to have the largest use of metal on polymer (MoP) hip replacements. An increasing number of the prevalence of revision surgery caused by adverse local tissue reaction in MoP THRs has recently been reported which is 3.2% at a mean follow-up of over 10 years (Hussey and McGrory, 2017). The issues are associated with debris/ion generated due to combined action of wear and corrosion termed as tribocorrosion/biotribocorrosion. As a result, the impact of these influential factors need to be assessed prior to implantation.

There are numbers of research questions related to hip implant failure which could be addressed during this preclinical testing using modern hip simulator. Such as, which interfaces are more prone to corrosion degradation? What is the tribocorrosion mechanism? etc. Often the results from preclinical testing showed deviance from clinical outcomes due to various reasons including testing protocol that is required to follow.

To address the above questions, Yang et al. (2022) have conducted an experiment under walking gait cycles to investigate the long-term biotribocorrosion at the MoP THR. His study revealed that the modular taper/trunnion junction was the main cause of MoP THR biotribocorrosion, not the bearing surfaces. The presence of tribochemical reaction layer on the surface proved the hypothesis as shown in the above figure (taken from the Yang et al. (2022) article and modified). The formation of this tribolayer could be impacted by number of ways. Even the changing of serum could have significant effect on the corrosion rate which may lead to poor prediction for clinical application. One of the limitation of his study is the lower number of loading cycles than recommended by ISO which need to be dealt in future.

 

Featured header image: Graphical abstract produced from figures taken from Yang et al. (2022)

References

Hussey D K, McGrory B J. Ten-year cross-sectional study of mechanically assisted crevice corrosion in 1,352 consecutive patients with metal-on-polyethylene total hip arthroplasty. J Arthroplasty 32(8): 2546–2551 (2017)

National Joint Registry 18th Annual Report 2021, https://www.njrcentre.org.uk/

Yang, S., Pu, J., Zhang, X., Zhang, Y., Cui, W., Xie, F., … & Jin, Z. (2022). A preliminary experimental investigation on the biotribocorrosion of a metal-on-polyethylene hip prosthesis in a hip simulator. Friction, 1-13.  

 

This article was written by MM Raihan as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Raihan is researching In-situ Measurement of Nano-scale Wear Utilising Advanced Sensors at the University of Leeds, UK.        

Industrial secondment at Evonik Industries AG

Picture: After visit to compounding floor, Marl (From left to right: Philip Engel (Head of Segment Medical Systems Europe, Evonik), Joscha Sandhusen (Compounding Technology, Evonik), Dilesh Raj Shrestha (PhD ESR, BioTrib-LTU), and Nazanin Emami (Professor, LTU)

I recently had the opportunity to visit two Evonik Industries AG sites in Germany (Marl and Darmstadt) as part of my industrial secondment. Evonik is one of the world’s largest specialty chemical companies, with a diverse business portfolio. Evonik is also active in the medical industry, manufacturing high-performance plastics like Poly Ether Ether Ketone (PEEK) for various implant applications. Evonik located at Marl Chemical Park, Evonik’s largest chemical park, where I spent my first week learning PEEK polymer processing and compounding. We were able to meet with experts in PEEK compounding development and have an in-depth discussion about current challenges and prospects.

I relocated to Evonik Darmstadt for the final three weeks of my secondment. In Darmstadt, Evonik has a tribology lab dedicated for material screening. I worked on the tribology test setup and wear data interpretation for medical implant applications. This provided me with an understanding of the clinically relevant tribological test setup required for material screening as well as the data interpretation techniques. I had the opportunity to meet with and speak with the medical implant team, where I learned about the industrial approach as well as their thoughts on moving forward with PEEK medical implant applications.

Finally, I’d like to express my gratitude to everyone who assisted in organizing this secondment and making it a fruitful learning experience.

This article was written by Dilesh Raj Shrestha as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Dilesh is researching the Development of 3D-printable, self-lubricated polymer composites with improved wear resistance for total joint replacement at Luleå University of Technology, Sweden.

Wait, We Need a PhD in 3D Printing? Part 4: Printing Gels

A study done by Julia et al. proved the possibility of using multi-material direct ink printing (4D printing) technology to integrate magnetic nanoparticles with hydrogels. The contactless in-air control of motions like rolling, jumping, and bending is realised because of the interactions between magnetic and nonmagnetic hydrogels. The programmability of patterns of the multi-material also enables its future potential in soft robotics

Visit the original paper below to find out more!

Simińska-Stanny, Julia, et al. “4D printing of patterned multimaterial magnetic hydrogel actuators.” Additive Manufacturing 49 (2022): 102506.

Starfish 3D printed responsive hydrogels by Dr Ali Mohammed:

Image of Starfish shaped responsive Hydrogel reporoduced with permission from Dr Ali Mohammed

Another fantastic work of 3D printed responsive hydrogels by Dr Ali Mohammed!

The superparamagnetic starfish-shaped hydrogel can be used for magnetically simulated soft robotics and actuators.

Check out the videos to see the 3D printed ‘starfish’ moving responsively to the magnet:

This post was written by Esperanza Shi as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Esperanza is researching the Optimisation of Scanning Strategies for 3D Printed Artificial Joints at Imperial College London, UK.

Wait, We Need a PhD in 3D Printing? Part 3: Open5x 5-axis 3D Printing

Turbine-like object printed by 5-axis 3d printing [1]

To improve the quality of printed overhanging structures and surfaces, to reduce the waste of materials of support structures and to reduce the printing time, 3D printers are ready to evolve into multi-axis. Freddie Hong, a PhD candidate at Imperial College London, has been designing 5-axis 3D printers and conformal slicing in an accessible and cheap way to bring these advantages to more individuals. With the rotating printing platform and the slicer designed for 5-axis 3D printers, the overhanging structures can be printed conformally, resulting in reinforced structural strengths.

Visit the video below to watch Freddie sharing more details!

Freddie made the hardware and software kits of open5x open resource, so check out the GitHub and upgrade your desktop 3D printer!

GitHub: https://github.com/FreddieHong19/Open5x

References:

[1] Hong, Freddie, et al. “Open5x: Accessible 5-axis 3D printing and conformal slicing.” CHI Conference on Human Factors in Computing Systems Extended Abstracts. 2022.

This post was written by Esperanza Shi as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Esperanza is researching the Optimisation of Scanning Strategies for 3D Printed Artificial Joints at Imperial College London, UK.

Wait, We Need a PhD in 3D Printing? Part 2: Flying 3D Printers

Breaking news from Imperial College London and Empa Switzerland that the research of flying 3D printers is featured as the cover of Nature (Volume 609 Issue 7928, 22 September 2022). Instead of sitting statically on the table like most 3d printers, this aerial robotic 3d printer prints structures in-flight, inspired by natural builders like wasps and bees.

The ‘ScanDrones’ work in pairs with the ‘BuildDrones’ enabling the monitoring of the print quality, thanks to a generic real-time model-predictive-control scheme. Flying 3D printers have been proven to have the potential in conducting constructions post-disaster or in places that are difficult to access.  Check out the video produced by the Imperial and Empa researchers below:

Visit the website and original paper below to find out more!

Imperial: https://www.imperial.ac.uk/news/239973/3d-printing-drones-work-like-bees/

Nature Paper: https://www.nature.com/articles/s41586-022-04988-4

Zhang, Ketao, et al. “Aerial additive manufacturing with multiple autonomous robots.” Nature 609.7928 (2022): 709-717.

This post was written by Esperanza Shi as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Esperanza is researching the Optimisation of Scanning Strategies for 3D Printed Artificial Joints at Imperial College London, UK.

Wait, We Need a PhD in 3D Printing? Part 1

Having been asked this question several times when I was trying to introduce myself and what I do with my PhD to someone I just met, I feel it’s time to update the general public on how cutting-edge research about this technology is looking like now. The fact is that the public no longer views 3D printing as ‘cutting-edge’ because 3D printing technology came out decades ago and has become so easy to access (you can easily buy one desktop 3D printer and set it up at home).

However, 3D printing is not just about the desktop 3D printer you can have at home that extrudes plastics. Just have a glance at this map, and you will understand that 3D printing is such a broad concept and there is much more it’s capable of.

Picture by Dr Usman Waheed

There’re so many aspects we can improve under each category to make the technology better, meanwhile, engineers and scientists never stopped exploring the potential and broadening the horizon of 3D printing. The map or we can say the world of 3D printing is still getting bigger and better, so we DO need PhDs in 3D printing!

I’m not saying this because I’m trying to defend myself as personally being a PhD in 3D printing. The 3 amazing examples I’m going to show you over the next two weeks are to convince you that we DO need PhDs in 3D printing.

This post was written by Esperanza Shi as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Esperanza is researching the Optimisation of Scanning Strategies for 3D Printed Artificial Joints at Imperial College London, UK.

PhD Life in Uppsala

About a year ago, to pursue my academic career I moved from Italy to Sweden, specifically to Uppsala, a lovely town near Stockholm. I am now a PhD student in the local university and in some way I feel that my undergraduate days are well behind me. But you know, Uppsala is a very special city full of students from all around the world who certainly “rule” the town. Here, even if you are no longer a student, you can easily feel like one again just walking into a specific neighborhood at a specific time of the day… Or should I say night?

This neighborhood is called Flogsta, it is located in the west part of the city and most of its inhabitants (basically everyone) are students at Uppsala University. But what’s special about this place you might ask? There, every evening at about 10 p.m. the “Flogsta Scream” can be heard. If you’re from Uppsala you will surely be familiar with this particular “ritual”, or at least have heard of it. Literally. If instead you don’t know anything about it, the Flogsta Scream is (as the name suggest) a scream, but it’s also something more than that. It is a collective act in which students scream together from windows, balconies and rooftops. According to the student population, this act is a kind of “safety valve” or “a cry of anguish” over the accumulated stress of the demands of college life.

Truth be told, it is just an occasion to socialize and make some noise together, but for Uppsala students it is something that you can count on every single day. Sometimes everyone need to scream a little in life, might as well do it the Uppsala way.

 

This article was written by Niccoló De Berardinis as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Niccoló is researching Bioimaging of biomaterials and biological characterization of 3D-printed alloys for reconstructive surgery at Uppsala University, Sweden.

ESRs André Plath and Giulio Cavaliere attend the 32nd Conference of the European Society of Biomaterials in Bordeaux

From the 4th to the 8th of September the European Society of Biomaterials (ESB) hosted its 32nd conference at Palais des Congrès, in Bordeaux, France. ESRs André Plath (ETH Zürich) and Giulio Cavaliere (U. Uppsala) presented some of their current results in poster format during the conference.
“The conference was a great opportunity for networking and building a strong basis for future collaborations. The plenary talks were not only inspiring but represented the top-notch science being developed right now. It was also great to see a good mixture of academics and industries. I commend the ESB for also organizing lunches and talks with senior researchers, industrials, and editors.” says André.

”We met plenty of people working on similar projects and it was a great context to exchange ideas and get insightful feedbacks on my work. Being my first conference I also learnt a lot of useful skills on how to present my research. A lot of the plenary talks were more focus on tissues engineering so it was a good opportunity to expand my knowledge outside my research field” says Giulio

This article was written by André Plath and Giulio Cavaliere as part of a series articles curated by BioTrib’s Early Stage Researchers.

André is one of BioTrib’s Early Stage Researcher‘s who is investigating Boundary Lubrication of Fibrous Scaffolds at ETH Zürich, Switzerland.

 

 

Giulio Cavaliere is investigating Additively manufactured biodegradable alloys for bone replacement at Uppsala University, Sweden.

On Outreach Activities

Earlier this year, I took a course titled “Research Introduction for New Ph.D. Students” at Uppsala University. In this course, I was informed of a main task of a university that may often be overlooked. I believe that most people know that two of the primary purposes of a university are education and research. However, there is another significant part of a university’s responsibility, and that is outreach. Universities conduct outreach activities to communicate their research activities to the broader public, especially those outside the academic community. Aside from increasing the general public’s interest in science and technology, a good outreach program may also be a platform for the long-term recruitment of students and researchers.

SciFest Uppsala Logo, taken from SLU website [2]
There are many outreach programs here at Uppsala, such as the annual SciFest arranged by Uppsala University and the Swedish University of Agricultural Sciences. From its website, SciFest is a “…festival with a wide range of workshops, shows, competitions, research meetings, and lectures”. This festival has activities for anyone, from kids to adults. Always attended by exhibitors from academia, government authorities, and technology companies, anyone who comes to SciFest will be sure to get a taste of research and science from different perspectives.

As university employees, BioTrib early-stage researchers are also responsible for conducting outreach activity. An outreach program does not have to be a festival, a workshop, or even anything physical. I think the BioTrib’s blog initiative is a good outreach program. With this blog, researchers affiliated with BioTrib can share snippets of our research and even issues within the academic communities to a broader audience. This is especially important for us as BioTrib’s research may significantly impact the medical world in the long term. I hope you’ve found our posts to be interesting and informative!

 

References

1. Uu.se
2. Slu.se
3. Scifest.se

 

This article was written by Vidhiaza Leviandhika as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Vidhiaza is researching the Development of Development of 3D-printed gradient alloys for joint implant component at Uppsala University, Sweden

A Limit to “Wonder Metal”

Titanium and its alloys are essential engineering materials. Owing to their fantastic combination of mechanical properties, they can be found in a variety of applications, such as jet engine blades and golf club heads. They are also valuable biomaterials due to their excellent corrosion resistance and biocompatibility. In the biomedical industry, titanium alloys found use in implant devices, for example, dental implants and the stem of a hip replacement. It is no wonder that they are called wonder material. Though their strength is many, titanium and its alloys’ use are still limited due to its apparent weakness, namely, its tribological properties. This means titanium alloys are not ideal in applications where they are in moving contact with another material/component.

Titanium’s poor wear characteristics have been well documented for decades. Among the many explanations, the three highly cited reasons for titanium’s poor tribological properties are [1]:

1. Low work-hardening capability
2. Insufficient protective capability from their tribo-oxides

In the biomedical industry, this means titanium and its alloys are not the best materials to use in joint replacement. In fact, titanium is an inferior material to cobalt-chromium alloys simply because titanium has a more damaging effect on the plastic liner of a joint component, which results in a lower life of the joint replacement as a whole [2].

Currently, there are many research studies that try to improve the wear characteristics of titanium. Naturally, many of those are focused on improving the surface of the material since the wear is a surface phenomenon. The advancement of metal additive manufacturing may also pave the way for more opportunities to improve the wear characteristics of titanium. Indeed, this is also my personal research focus. With the many controllable parameters in additive manufacturing, e.g., scanning strategies, laser parameters, and powder composition, I hope to manufacture a better titanium surface that will be more appropriate for tribological properties. When I achieve that, you’ll be sure to hear it in BioTrib’s blog!

References:

[1] X. X. Li, Q. Y. Zhang, Y. Zhou, J. Q. Liu, K. M. Chen, and S. Q. Wang, “Mild and Severe Wear of Titanium Alloys,” Tribol. Lett., vol. 61, no. 2, p. 14, Feb. 2016, doi: 10.1007/s11249-015-0637-8.
[2] M. Long and H. J. Rack, “Titanium alloys in total joint replacement—a materials science perspective,” Biomaterials, vol. 19, no. 18, pp. 1621–1639, Sep. 1998, doi: 10.1016/S0142-9612(97)00146-4.

 

This article was written by Vidhiaza Leviandhika as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Vidhiaza is researching the Development of Development of 3D-printed gradient alloys for joint implant component at Uppsala University, Sweden

World Economic Forum and ETH – RETHINKING LIVING

In May 2022, around 2,000 business leaders and politicians have been in Davos, in Switzerland, for the World Economic Forum’s (WEF) annual meeting. The WEF is an international non-governmental and lobbying organization based in Cologny, canton of Geneva, Switzerland. With the mission to “improve the state of the world by engaging business, political, academic, and other leaders of society to shape global, regional, and industry agendas”, it was founded in 1971 by German engineer and economist Klaus Schwab. The WEF is mostly known for its annual meeting in Davos. Over the course of five days, 3,000 paying members and selected participants – including investors, business leaders, politicians, economists, celebrities, and journalists – discuss global issues.

During the WEF Annual Meeting 2022, ETH Zurich hosts several exclusive events in its RETHINKING LIVING Pavilion. RETHINKING LIVING, created in the spirit of ETH alumnus A. Einstein: ”The important thing is not to stop questioning”, brings together scientists, industry experts, and outstanding global thinkers from ETH Zurich and across the world with the aim to re-think different conceptions of living, re-evaluate life choices, and re-consider the changes needed in a post-pandemic world. Will new technologies build a more sustainable, resilient, and equitable world? On the occasion of the WEF Annual Meeting and to incite exchange, three pioneering exhibits explore the human coexistence in different dimensions: the physical, “White Tower”, the cyber-physical, ”no1s1″ house, and the completely virtual, ”Digital Einstein”.

The White Tower (Cultural site and highest 3d printed building – see header image, credit to Hansmeyer/Dillenburger).

The White Tower is a 29-meter tall, entirely 3D printed building located along the Julier mountain pass in the remote Swiss village of Mulegns. The tower offers exhibitions, performances, and music. It aims to revitalize a village in decline and to describe the rich cultural history of Mulegns and its surroundings. A large portion of the tower will be built in an on-site fabrication lab. In this way, the tower provides digital skills to the mountain regions and advances local trade. It serves as a demonstration of the groundbreaking possibilities of computational design and digital fabrication, which will fundamentally change conventional buildings in the years to come.

No1s1 (no-one’s-one) rethinks collective goods and ownership. It is the first house on the blockchain that can be used by anyone but it belongs to no one. It runs itself and rents itself out. This concept of self-ownership aims to create a digital ecosystem of people, and artificial things. The prototype is a meditation cabin that disattends the usual economic and social expectations. It is decorated with LED lights, connected to a solar panel, and has comfortable seats for meditation inside. No1s1 aims to become an alternative model for real estate and infrastructure.

No1s1 Digital House. Credit Hongyang Wang

The final idea is a “Nature 2.0’’’, a self-sustaining human infrastructure that manages and regulates itself like a natural ecosystem. To celebrate the 100 years of Einstein’s Nobel Prize in Physics, ETH Zurich brings its most famous alumnus to life as an animated character. The implemented platform offers an opportunity to interact with a digital Einstein.

Albert Einstein studied at ETH Zurich between 1896 and 1900, graduating with a diploma in mathematics and natural sciences, and afterward obtained his doctorate at the University of Zurich. After some time in Bern, Einstein returned to his alma mater as a professor of theoretical physics between 1912 and 1914. In the interactive platform, a digital Einstein talks about his years in Zurich. The project is part of the university’s strategy to boost dialogue with society and to bring young people closer to science. Digital Einstein will be taking up his post at various locations around ETH and, eventually, abroad.

Nature 2.0 – brining Einstein to life. Credit: ETH Zurich / Nicole Davidson

References

https://ethz.ch/en/news-and-events/eth-news/news/2022/05/eth-at-wef-rethinking-living.html

This article was written by Elisa Bissacco as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

She is studying a PhD in Tribological Characteristics of Nanofibrous Electrospun Materials at ETH Zurich.

Porosity control and influence in 3D bioprinted scaffolds

Header Image: Schematic representation of scaffolds characterized by three different lay-down patterns. (a) 0◦/90◦. (b) 0◦/60◦/120◦. (c) 0◦/45◦/90◦/135◦. [1]

The main objective of 3D bioprinting is to recreate human tissues with the same mechanical, structural and biological properties as the corresponding native tissue, in order to solve the problems associated with conventional transplantation techniques (donor site morbidity, organ shortage, etc.). For this purpose, different cell types combined with different biomaterials have been bioprinted according to specific models, but obtaining a 3D scaffold with the desired properties remains a challenge.

The advantage of 3D bioprinting over conventional scaffold fabrication techniques is the ability to control the 3D architecture of scaffolds through parameters such as pore size and geometry. Pore size and shape influence the resulting mechanical properties as well as cell behavior and tissue growth over time. Domingos et al. showed that for a lay down pattern of 0◦/90◦ (filament orientation between layers) with different pore sizes, poly(ε-caprolactone) scaffolds with smaller pores exhibit significantly higher stiffness under compressive conditions, which is an important property in applications such as bone tissue engineering. For different pore shapes with the following lay down pattern: 0◦/90◦, 0◦/60◦/120◦ and 0◦/45◦/90◦/135◦ (see figure) and the same porosity, the increasing number of angles between the filaments of the different layers leads to an increase in the deformability of the construct under compressive conditions.

Regarding the influence of architecture on cell behavior, viability and proliferation of human mesenchymal stem cells (hMSCs) were studied for 21 days and showed that larger pores with a lay down pattern of 0◦/90◦ improve viability and proliferation.

References

[1] Domingos, M., et al. “THE FIRST SYSTEMATIC ANALYSIS OF 3D RAPID PROTOTYPED POLY (e-CAPROLACTONE) SCAFFOLDS MANUFACTURED THROUGH BIOCELL PRINTING: EFFECT OF PORE SIZE AND GEOMETRY ON COMPRESSIVE MECHANICAL BEHAVIOR AND IN VITRO HMSC VIABILITY.” 1758-5082 5 (2013).

This article was written by Marie Moulin as part of an ongoing series of scientific communications written and curated by BioTrib’s Early Stage Researchers.

Marie is researching the Bioprinting of Bone and Cartilage at Uppsala University, Sweden.