Tag Archives: 3D printing

Electronics repairs in space made possible with nanoink and 3D printing?

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Researchers — as well as a toy Cy the Cyclone — test their nanoink and printer technologies during a NASA microgravity flight. Pictured, left to right, are: Fei Liu, Yanhua Huang, Matthew Marander, Xuepeng Jiang and Pavithra Premaratne. Photo courtesy of Shan Jiang.

They’re not making any promises but there are possibilities according to a November 21, 2024 news item on phys.org,

An Iowa State University engineer floats in the air while other researchers hang tight to a metal frame surrounding and supporting their special printer. [A Cy the Cyclone toy mascot all dressed up as an astronaut also floats above the busy researchers hunched over their experiment.] It’s not the usual photo you see in a research paper. Tests aboard microgravity flights aren’t your typical materials experiments, either.

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A November 20, 2024 Iowa State University news release (also on EurekAlert but published November 21, 2024), which originated the news item, shows where curiosity can take you,

The flight path to these experiments began when a research team led by Iowa State’s Shan Jiang, an associate professor of materials science and engineering, and Hantang Qin, formerly of Iowa State who’s now an assistant professor of industrial and systems engineering at the University of Wisconsin-Madison, wondered if their ink and printer technologies would work in the zero gravity of space.

The ink features silver nanoparticles synthesized with biobased polymers. After a heat treatment, the ink can conduct electricity and can therefore print electric circuits. The printer uses electrohydrodynamic printing, or 3D printing that jets ink under an electric field at resolutions of millionths of a meter. The electric field could eliminate the need for gravity to help deposit ink.

If the technologies work together in zero gravity, astronauts could use them to make electric circuits for spacecraft or equipment repairs. And astronauts might manufacture high-value electronic components in the special, zero-gravity environment of space.

NASA [(US) National Space and Aeronautics Agency] wondered if it would work, too.

Diving into microgravity

Researchers bolted the printer to the floor of a jet and prepared for a “roller coaster, basically,” Jiang said.

The NASA plane would continuously climb and dive, going in cycles from about 24,000 feet over Florida to 32,000 feet then back to 24,000. The dive phase produced about 10 seconds of pure zero gravity.

“It was exciting and new,” Jiang said.

Motion sickness was a problem for some. Others enjoyed the thrill of it. Jiang felt “frozen” the first time he experienced microgravity. “I was blank.”

But that didn’t last: “There was so much time and investment in this project. We wanted to achieve good results.”

But printing for a few seconds at a time on a microgravity flight “is a very challenging experiment,” Jiang said. “It’s so easy on the ground where everything is stable. But if anything gets loose during the flight, you lose your printing.”

The first microgravity flight was a good example. The printer wasn’t adequately secured against the plane’s shakes and vibrations.

“These are very intense experiments that require a lot of teamwork and preparation,” Jiang said.

So, the team went back to work, made some changes, made more test flights and produced better results.

“This proof-of-concept microgravity experiment proves the unique capability of (electrohydrodynamic) printing under zero-gravity conditions and opens a new venue for future on-demand manufacturing in space,” the researchers wrote in a paper published by the journal American Chemical Society Applied Materials & Interfaces. (…)

Making a new nanoink

The key innovation by Jiang’s research group was developing a new laboratory method to synthesize the ink with its silver nanoparticles.

“This is a new combination of materials and so we needed a new recipe to make the ink,” Jiang said.

Grants from the NASA Iowa Space Grant Consortium and the NASA Iowa Established Program to Stimulate Competitive Research supported the project.

Both programs “strive to support innovative and leading research in Iowa,” said Sara Nelson, director of the programs and an Iowa State adjunct assistant professor of aerospace engineering. “We are thrilled to have supported Dr. Jiang’s research. His work has helped to build Iowa’s research infrastructure and is an important part of NASA’s strategic mission.”

The project also makes use of an abundant Iowa resource, plant biomass.

The ink includes a biobased polymer called 2-hydroxyethyl cellulose, which is typically used as a thickening agent. But it is also a cost-effective, biocompatible, versatile and stable material for the inks necessary for high-resolution ink jet printing under an electric field.

“There is a lot of biomass in Iowa,” Jiang said. “So, we’re always trying to use these biobased molecules. They make a wonderful polymer that does all the tricks for us.”

Jiang called that “the biggest surprise of this research. We didn’t know that before. Now we know what we can do with these biobased polymers.”

The Iowa State University Research Foundation has filed a patent on the new nanoink and the technology is currently available for licensing.

“This success is really just the beginning,” Jiang said. “As humanity ventures deeper into space, the need for on-demand manufacturing of electronics in orbit is no longer science fiction; it is a necessity.”

Next up for the researchers could be development of 3D space printing for other electronic components such as semiconductors.

After all, Jiang said, “You can’t just make one component and assemble an electronic device.”

Here’s a link to and a citation for the paper,

Silver Nano-Inks Synthesized with Biobased Polymers for High-Resolution Electrohydrodynamic Printing Toward In-Space Manufacturing by Tyler Kirscht, Liangkui Jiang, Fei Liu, Xuepeng Jiang, Matthew Marander, Ricardo Ortega, Hantang Qin, Shan Jiang. ACS Appl. Mater. Interfaces 2024, 16, 33, 44225–44235 DOI: https://doi.org/10.1021/acsami.4c07592 Published: July 30, 2024 Copyright © 2024 American Chemical Society

This paper is behind a paywall.

Miniature, soft lithium-ion battery constructed from biocompatible hydrogel droplets for bio-integrated devices

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The original headline for the University of Oxford press release was “Batteries for miniature bio-integrated devices and robotics” but it’s not clear to me what they mean by robotics (soft robots? robotic prostheses? something else?).

An October 25, 2024 news item on ScienceDaily announces the research,

University of Oxford researchers have made a significant step towards realising miniature, soft batteries for use in a variety of biomedical applications, including the defibrillation and pacing of heart tissues. The work has been published today [October 25, 2024] in the journal Nature Chemical Engineering.

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An October 28, 2024 University of Oxford press release (also on EurekAlert but published October 25, 2024), which originated the lightly edited news item and posting on EurekAlert, provides more technical detail about this advance, Note: Links have been removed,

The development of tiny smart devices, smaller than a few cubic millimeters, demands equally small power sources. For minimally invasive biomedical devices that interact with biological tissues, these power sources must be fabricated from soft materials. Ideally, these should also have features such as high capacity, biocompatibility and biodegradability, triggerable activation, and the ability to be controlled remotely. To date, there has been no battery that can fulfil these requirements all at once.

To address these requirements, researchers from the University of Oxford’s Department of Chemistry and Department of Pharmacology have developed a miniature, soft lithium-ion battery constructed from biocompatible hydrogel droplets. Surfactant-supported assembly (assembly aided by soap-like molecules), a technique reported by the same group last year in the journal Nature (DOI: 10.1038/s41586-023-06295-y), is used to connect three microscale droplets of 10 nanolitres volume. Different lithium-ion particles contained in each of the two ends then generate the output energy.

‘Our droplet battery is light-activated, rechargeable, and biodegradable after use. To date, it is the smallest hydrogel lithium-ion battery and has a superior energy density’ said Dr Yujia Zhang (Department of Chemistry, University of Oxford), the lead researcher for the study and a starting Assistant Professor at the École Polytechnique Fédérale de Lausanne. ‘We used the droplet battery to power the movement of charged molecules between synthetic cells and to control the beating and defibrillation of mouse hearts. By including magnetic particles to control movement, the battery can also function as a mobile energy carrier.’

Proof-of-concept heart treatments were carried out in the laboratory of Professor Ming Lei (Department of Pharmacology), a senior electrophysiologist in cardiac arrhythmias. He said: ‘Cardiac arrhythmia is a leading cause of death worldwide. Our proof-of-concept application in animal models demonstrates an exciting new avenue of wireless and biodegradable devices for the management of arrhythmias.’

Professor Hagan Bayley (Department of Chemistry), the research group leader for the study, said: ‘The tiny soft lithium-ion battery is the most sophisticated in a series of microscale power packs developed by Dr Zhang and points to a fantastic future for biocompatible electronic devices that can operate under physiological conditions.’

The researchers have filed a patent application through Oxford University Innovation. They envisage that the tiny versatile battery, particularly relevant to small-scale robots for bioapplications, will open up new possibilities in various areas including clinical medicine.

Here’s a link to and a citation for the paper,

A microscale soft lithium-ion battery for tissue stimulation by Yujia Zhang, Tianyi Sun, Xingyun Yang, Linna Zhou, Cheryl M. J. Tan, Ming Lei & Hagan Bayley. Nature Chemical Engineering volume 1, pages 691–701 (2024) DOI: https://doi.org/10.1038/s44286-024-00136-z Published online: 25 October 2024 Issue Date: November 2024

This paper is open access.

Now, I want to highlight a few items from the paper’s introduction, Note: Links have been removed,

The miniaturization of electronic devices is a burgeoning area of research1,2,3. Therefore, the development of tiny batteries to power these devices is of critical importance, and techniques such as three-dimensional (3D) printing4,5,6 and micro-origami assembly7 [emphases mine] are beginning to have an impact. For minimally invasive applications in biomedicine, batteries are also preferred to be soft, biocompatible and biodegradable, with additional functionality and responsiveness, such as triggerable activation and remote-controlled mobility8. However, at present, such a multifunctional microscale soft battery is not available. Although hydrogel-based lithium-ion (Li-ion) batteries demonstrate some of these features9,10,11,12, none currently exhibits microscale fabrication of the battery architecture, in terms of self-assembled integration of hydrogel-based cathode, separator and anode at the submillimeter level. Manual assembly of precrosslinked compartments11 or multistep deposition and crosslinking4 is necessary to avoid the mixing of materials from different compartments at the pregel (liquid) state or during the gelation process. This limitation not only makes it difficult to shrink hydrogel-based functional architectures but also hinders the implementation of high-density energy storage.

Toward that end, Zhang et al. have reported a miniaturized ionic power source by depositing lipid-supported networks of nanoliter hydrogel droplets13. The power source mimics the electrical eel [emphasis mine] by using internal ion gradients to generate ionic current14, and can induce neuronal modulation. However, the ionic power source has several limitations [emphasis mine] that should be addressed. First, the stored salt gradient produces less power than conventional Li-ion batteries, and the device cannot be fully recharged. Second, activation of the power source relies on temperature-triggered gelation and oil for buffer exchange, which is a demanding requirement. Third, the functionality of the power source is limited to the generation of ionic output, leaving the full versatility of synthetic tissues unexploited15,16,17. Last, but not least, while the power source can modulate the activity of neural microtissues, organ-level stimulation necessitates a higher and more stable output performance in physiological environments18.

Here, we present a miniature, soft, rechargeable Li-ion droplet battery (LiDB) made by depositing self-assembling [emphasis mine], nanoliter, lipid-supported, silk hydrogel droplets. The tiny hydrogel compartmentalization produces a superior energy density. The battery is switched on by ultraviolet (UV) light, which crosslinks the hydrogel and breaks the lipid barrier between droplets. The droplets are soft, biocompatible and biodegradable. The LiDBs can power charge molecule translocation between synthetic cells, defibrillate mouse hearts with ventricular arrhythmias and pace heart rhythms. Further, the LiDB can be translocated from one site to another magnetically.

This team has integrated a number of cutting edge (I think you can still call them that) techniques such as 3D printing and origami along with inspiration from electric eels (biomimicry) for using light as a power source. .Finally, there’s self-assembly or, as it’s sometimes known, bottom-up engineering, just like nature.

This work still needs to be tested in human clinical trials but taking that into account: Bravo to the researchers!

3D printing method makes band-aids for your heart

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Matthew Davidson, a Research Associate with the University of Colorado demonstrates a 3D printed biomaterials for use inside the body including bandages that could be put on a beating human heart in Jason Burdick’s lab. (Photo by Casey A. Cass/University of Colorado)

Soft, strong, and flexible, that’s what you need if you’re going to apply a bandage to a heart and according to an August 1, 2024 news item on phys.org, researchers have developed a promising new material,

In the quest to develop life-like materials to replace and repair human body parts, scientists face a formidable challenge: Real tissues are often both strong and stretchable and vary in shape and size.

A CU [Colorado University] Boulder-led team, in collaboration with researchers at the University of Pennsylvania, has taken a critical step toward cracking that code. They’ve developed a new way to 3D print material that is at once elastic enough to withstand a heart’s persistent beating, tough enough to endure the crushing load placed on joints, and easily shapable to fit a patient’s unique defects.

Better yet, it sticks easily to wet tissue.

Their breakthrough, described in the Aug. 2 [2024] edition of the journal Science, helps pave the way toward a new generation of biomaterials, from internal bandages that deliver drugs directly to the heart to cartilage patches and needle-free sutures.

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An August 1, 2024 University of Colorado at Boulder news release (also on EurekAlert) by Lisa Marshall and Nicholas Goda, which originated the news item, provides more detail about the research and the challenges, Note: A link has been removed,

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“Cardiac and cartilage tissues are similar in that they have very limited capacity to repair themselves. When they’re damaged, there is no turning back,” said senior author Jason Burdick, a professor of chemical and biological engineering at CU Boulder’s BioFrontiers Institute. “By developing new, more resilient materials to enhance that repair process, we can have a big impact on patients.”

Worm ‘blobs’ as inspiration

Historically, biomedical devices have been created via molding or casting, techniques which work well for mass production of identical implants but aren’t practical when it comes to personalizing those implants for specific patients. In recent years, 3D printing has opened a world of new possibilities for medical applications by allowing researchers to make materials in many shapes and structures.

Unlike typical printers, which simply place ink on paper, 3D printers deposit layer after layer of plastics, metals or even living cells to create multidimensional objects.

One specific material, known as a hydrogel (the stuff that contact lenses are made of), has been a favorite prospect for fabricating artificial tissues, organs and implants.

But getting these from the lab to the clinic has been tough because traditional 3D-printed hydrogels tend to either break when stretched, crack under pressure or are too stiff to mold around tissues.

“Imagine if you had a rigid plastic adhered to your heart. It wouldn’t deform as your heart beats,” said Burdick. “It would just fracture.”

To achieve both strength and elasticity within 3D printed hydrogels, Burdick and his colleagues took a cue from worms, which repeatedly tangle and untangle themselves around one another in three-dimensional “worm blobs” that have both solid and liquid-like properties. Previous research has shown that incorporating similarly intertwined chains of molecules, known as “entanglements,” can make them tougher.

Their new printing method, known as CLEAR (for Continuous-curing after Light Exposure Aided by Redox initiation), follows a series of steps to entangle long molecules inside 3D-printed materials much like those intertwined worms.

When the team stretched and weight-loaded those materials in the lab (one researcher even ran over a sample with her bike) they found them to be exponentially tougher than materials printed with a standard method of 3D printing known as Digital Light Processing (DLP). Better yet: They also conformed and stuck to animal tissues and organs.

“We can now 3D print adhesive materials that are strong enough to mechanically support tissue,” said co-first author Matt Davidson, a research associate in the Burdick Lab. “We have never been able to do that before.”

Revolutionizing care

Burdick imagines a day when such 3D-printed materials could be used to repair defects in hearts, deliver tissue-regenerating drugs directly to organs or cartilage, restrain bulging discs or even stitch people up in the operating room without inflicting tissue damage like a needle and suture can.

His lab has filed for a provisional patent and plans to launch more studies soon to better understand how tissues react to the presence of such materials.

But the team stresses that their new method could have impacts far beyond medicine—in research and manufacturing too. For instance, their method eliminates the need for additional energy to cure, or harden, parts, making the 3D printing process more environmentally friendly.

“This is a simple 3D processing method that people could ultimately use in their own academic labs as well as in industry to improve the mechanical properties of materials for a wide variety of applications,” said first author Abhishek Dhand, a researcher in the Burdick Lab and doctoral candidate in the Department of Bioengineering at the University of Pennsylvania. “It solves a big problem for 3D printing.”

Here’s a link to and a citation for the paper,

Additive manufacturing of highly entangled polymer networks by Abhishek P. Dhand, Matthew D. Davidson, Hannah M. Zlotnick, Thomas J. Kolibaba, Jason P. Killgore, and Jason A. Burdick. Science 1 Aug 2024 Vol 385, Issue 6708 pp. 566-572 DOI: 10.1126/science.adn692

This paper is behind a paywall.

Aerogels that are 3D printed from nanocellulose

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The one on the far right looks a bit like a frog (to me),

Caption: Complexity and lightness: Empa researchers have developed a 3D printing process for biodegradable cellulose aerogel. Credit: Empa

An April 4, 2024 Swiss Federal Laboratories for Materials Science and Technology (EMPA) press release (also on EurekAlert) describes some interesting possibilities for nanocellulose,

At first glance, biodegradable materials, inks for 3D printing and aerogels don’t seem to have much in common. All three have great potential for the future, however: “green” materials do not pollute the environment, 3D printing can produce complex structures without waste, and ultra-light aerogels are excellent heat insulators. Empa researchers have now succeeded in combining all these advantages in a single material. And their cellulose-based, 3D-printable aerogel can do even more.

The miracle material was created under the leadership of Deeptanshu Sivaraman, Wim Malfait and Shanyu Zhao from Empa’s Building Energy Materials and Components laboratory, in collaboration with the Cellulose & Wood Materials and Advanced Analytical Technologies laboratories as well as the Center for X-ray Analytics. Together with other researchers, Zhao and Malfait had already developed a process for printing silica aerogels in 2020. No trivial task: Silica aerogels are foam-like materials, highly open porous and brittle. Before the Empa development, shaping them into complex forms had been pretty much impossible. “It was the logical next step to apply our printing technology to mechanically more robust bio-based aerogels,” says Zhao.

The researchers chose the most common biopolymer on Earth as their starting material: cellulose. Various nanoparticles can be obtained from this plant-based material using simple processing steps. Doctoral student Deeptanshu Sivaraman used two types of such nanoparticles – cellulose nanocrystals and cellulose nanofibers – to produce the “ink” for printing the bio-aerogel.

Over 80 percent water

The flow characteristics of the ink are crucial in 3D printing: Tt must be viscous enough in order to hold a three-dimensional shape before solidification. At the same time, however, it should liquefy under pressure so that it can flow through the nozzle. With the combination of nanocrystals and nanofibers, Sivaraman succeeded in doing just that: The long nanofibers give the ink a high viscosity, while the rather short crystals ensure that it has shear thinning effect so that it flows more easily during extrusion.

In total, the ink contains around twelve percent cellulose – and 88 percent water. “We were able to achieve the required properties with cellulose alone, without any additives or fillers,” says Sivaraman. This is not only good news for the biodegradability of the final aerogel products, but also for its heat-insulating properties. To turn the ink into an aerogel after printing, the researchers replace the pore solvent water first with ethanol and then with air, all while maintaining shape fidelity. “The less solid matter the ink contains, the more porous the resulting aerogel,” explains Zhao.

This high porosity and the small size of the pores make all aerogels extremely effective heat insulators. However, the researchers have identified a unique property in the printed cellulose aerogel: It is anisotropic. This means its strength and thermal conductivity are direction-dependent. “The anisotropy is partly due to the orientation of the nanocellulose fibers and partly due to the printing process itself,” says Malfait. This allows the researchers to control in which axis the printed aerogel piece should be particularly stable or particularly insulating. Such precisely crafted insulating components could be used in microelectronics, where heat should only be conducted in a certain direction.

A lot of potential applications in medicine

Although the original research project, which was funded by the Swiss National Science Foundation (SNSF), was primarily interested in thermal insulation, the researchers quickly saw another area of application for their printable bio-aerogel: medicine. As it consists of pure cellulose, the new aerogel is biocompatible with living tissues and cells. Its porous structure is able to absorb drugs and then release them into the body over a long period of time. And 3D printing offers the possibility of producing precise shapes that could, for instance, serve as scaffolds for cell growth or as implants.

A particular advantage is that the printed aerogel can be rehydrated and re-dried several times after the initial drying process without losing its shape or porous structure. In practical applications, this would make the material easier to handle: It could be stored and transported in dry form and only be soaked in water shortly before use. When dry, it is not only light and convenient to handle, but also less susceptible to bacteria – and does not have to be elaborately protected from drying out. “If you want to add active ingredients to the aerogel, this can be done in the final rehydration step immediately before use,” says Sivaraman. “Then you don’t run the risk of the medication losing its effectiveness over time or if it is stored incorrectly.”

The researchers are also working on drug delivery from aerogels in a follow-up project – with less focus on 3D printing for now. Shanyu Zhao is collaborating with researchers from Germany and Spain on aerogels made from other biopolymers, such as alginate and chitosan, derived from algae and chitin respectively. Meanwhile, Wim Malfait wants to further improve the thermal insulation of cellulose aerogels. And Deeptanshu Sivaraman has completed his doctorate and has since joined the Empa spin-off Siloxene AG, which creates new hybrid molecules based on silicon.

Fascinating work and here’s a link to and a citation for the paper,

Additive Manufacturing of Nanocellulose Aerogels with Structure-Oriented Thermal, Mechanical, and Biological Properties by Deeptanshu Sivaraman, Yannick Nagel, Gilberto Siqueira, Parth Chansoria, Jonathan Avaro, Antonia Neels, Gustav Nyström, Zhaoxia Sun, Jing Wang, Zhengyuan Pan, Ana Iglesias-Mejuto, Inés Ardao, Carlos A. García-González, Mengmeng Li, Tingting Wu, Marco Lattuada, Wim J. Malfait, Shanyu Zhao. Advanced Science DOI: https://doi.org/10.1002/advs.202307921 First published: 13 March 2024

This paper is open access.

You can find Siloxene AG here.

3D printed nanocellulose for green architectural applications

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It’s not happening next week but it is a promising step forward if you’re looking for nancellulose applications. From a February 7, 2024 news item on Nanowerk, Note: A link has been removed,

For the first time, a hydrogel material made of nanocellulose and algae has been tested as an alternative, greener architectural material. The study, from Chalmers University of Technology in Sweden and the Wallenberg Wood Science Center, shows how the abundant sustainable material can be 3D printed into a wide array of architectural components, using much less energy than conventional construction methods.

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Caption: 3D printed nanocellulose upscaled for green architectural applications. Credit: Chalmers University of Technology | Emma Fry

A February 6, 2024 Chalmers University of Technology press release (also on EurekAlert but published February 7, 2024), which originated the news item,

The construction industry today consumes 50 percent of the world’s fossil resources, generates 40 percent of global waste and causes 39 percent of global carbon dioxide emissions. There is a growing line of research into biomaterials and their applications, in order to transition to a greener future in line with, for example, the European Green Deal.

Nanocellulose is not a new biomaterial, and its properties as a hydrogel are known within the field of biomedicine, where it can be 3D printed into scaffolds for tissue and cell growth, due to its biocompatibility and wetness. But it has never been dried and used as an architectural material before.

“For the first time we have explored an architectural application of nanocellulose hydrogel. Specifically, we provided the so far missing knowledge on its design-related features, and showcased, with the help of our samples and prototypes, the tuneability of these features through custom digital design and robotic 3D printing,” says Malgorzata Zboinska, lead author of the study from Chalmers University of Technology.

The team used nanocellulose fibres and water, with the addition of an algae-based material called alginate. The alginate allowed the researchers to produce a 3D printable material, since the alginate added an extra flexibility to the material when it dried.

Cellulose is coined as the most abundant eco-friendly alternative to plastic, as it is one of the byproducts of the world’s largest industries. “The nanocellulose used in this study can be acquired from forestry, agriculture, paper mills and straw residues from agriculture. It is a very abundant material in that sense,” says Malgorzata Zboinska.

3D printing and nanocellulose/ A resource efficient technique

The architectural industry is today surrounded by access to digital technologies which allows for a wider range of new techniques to be used, but there is a gap in the knowledge of how these techniques can be applied. According to the European Green Deal, as of 2030, buildings in Europe must be more resource-efficient, and this can be achieved through elevated reuse and recycling of materials, such as with nanocellulose, an upcycled, byproduct from industry. At the same time as buildings are to become more circular, cutting-edge digital techniques are highlighted as important leverages for achieving these goals.

“3D printing is a very resource efficient technique. It allows us to make products without other things such as dies and casting forms, so there is less waste material. It is also very energy efficient. The robotic 3D printing system we employ does not use heat, just air pressure. This saves a lot of energy as we are only working at room temperature,” says Malgorzata Zboinska.

The energy efficient process relies on the shear thinning properties of the nanocellulose hydrogel. When you apply pressure it liquifies allowing it to be 3D printed, but when you take away the pressure it maintains its shape. This allows the researchers to work without the energy intensive processes that are commonplace in the construction industry.

Malgorzata Zboinska and her team designed many different toolpaths to be used in the robotic 3D printing process to see how the nanocellulose hydrogel would behave when it dried in different shapes and patterns. These dried shapes could then be applied as a basis to design a wide array of architectural standalone components, such as lightweight room dividers, blinds, and wall panel systems. They could also form the basis for coatings of existing building components, such as tiles to clad walls, acoustic elements for damping sound, and combined with other materials to clad skeleton walls.

The future of greener building materials

“Traditional building materials are designed to last for hundreds of years. Usually, they have predictable behaviours and homogenous properties. We have concrete, glass and all kinds of hard materials that endure and we know how they will age over time. Contrary to this, biobased materials contain organic matter, that is from the outset designed to biodegrade and cycle back into nature. We, therefore, need to acquire completely new knowledge on how we could apply them in architecture, and how we could embrace their shorter life cycle loops and heterogenous behaviour patterns, resembling more those found in nature rather than in an artificial and fully controlled environment. Design researchers and architects are now intensely searching for ways of designing products made from these materials, both for function and for aesthetics,” says Malgorzata Zboinska.

This study provides the first steps to demonstrate the upscaling potentials of ambient-dried, 3D-printed nanocellulose membrane constructs, as well as a new understanding of the relationship between the design of the material’s deposition pathways via 3D printing, and the dimensional, textural, and geometric effects in the final constructs. This knowledge is a necessary stepping stone that will allow Malgorzata Zboinska and her team to develop, through further research, applications of nanocellulose in architectural products that need to meet specific functional and aesthetic user requirements.  

“The yet not fully known properties of novel biobased materials prompt architectural researchers to establish alternative approaches to designing these new products, not only in terms of the functional qualities, but also the acceptance from the users. The aesthetics of biobased materials are an important part of this. If we are to propose these biobased materials to society and people, we need to work with the design as well. This becomes a very strong element for the acceptance of these materials. If people do not accept them, we will not reach the goals of a circular economy and sustainable built environment”.

More about the research:

The research is presented in a paper: “Robotically 3D printed architectural membranes from ambient dried cellulose nanofibril-alginate hydrogel”, published in the journal Materials and Design.

The researchers involved in the study are Malgorzata A. Zboinska, Sanna Sämfors and Paul Gatenholm. The researchers were active at Chalmers University of Technology and the Wallenberg Wood Science Center, both in Sweden, at the time of the study.

This work was supported by Adlerbertska Research Foundation and Chalmers University of Technology’s Area of Advance Materials Science. The Knut and Alice Wallenberg Foundation is gratefully acknowledged for funding the Wallenberg Wood Science Center. The authors would also like to recognise the contribution of Karl Åhlund, who assisted in the robotic extrusion system development.

Fact box – previous research:

Printing with nanocellulose was first developed at Chalmers University of Technology within the Wallenberg Wood Science Center in 2015. This is the first time this technology is being scaled up towards applications in buildings.

Here’s a link to and a citation for the paper,

Robotically 3D printed architectural membranes from ambient dried cellulose nanofibril-alginate hydrogel by Malgorzata A. Zboinska, Sanna Sämfors, Paul Gatenholm. Materials & Design Volume 236, December 2023, 112472 DOI: https://doi.org/10.1016/j.matdes.2023.112472

This paper appears to be open access.

For the curious, here’s The European Green Deal.

Chaos science, 3d printing, and jewellery

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Caption: The chaotic shapes depicted in this image, printed in bronze, are the first the group have made. They represent the first step in the transformation from chaos to manufacturable forms. Credit: Francesca Bertacchini, Pietro S. Pantano, Eleonora Bilotta

This reminds me of Viking (and maybe Celtic too) jewellery but it’s all based on chaos theory according to a January 24, 2023 news item on phys.org (Note: Links have been removed),

The further out in time, the more unreliable a weather forecast. That’s because small variations in initial weather conditions can completely change the entire system, making it unpredictable. Put another way, in the “butterfly effect,” an insect can flap its wings and create a microscopic change in initial conditions that leads to a hurricane halfway around the world.

This chaos is seen everywhere, from weather to labor markets to brain dynamics. And now, in the journal Chaos, researchers from the University of Calabria explored how to turn the twisting, fractal structures behind the science into jewelry with 3D printing.

A January 24, 2023 American Institute of Physics news release (also on EurekAlert), which originated the news item, describes the difficulty of transforming chaos into jewellery,

The jewelry shapes are based on the Chua circuit, a simple electronic system that was the first physical, mathematical, and experimental proof of chaos. Instead of an ordinary circuit, which produces an oscillating current, Chua’s circuit results in oscillations that never repeat.

“These chaotic configurations, called strange attractors, are complex structures that had never been observed before,” said author Eleonora Bilotta. “The depictions of such structures are strikingly beautiful, continually shifting when the point of view is changing. Jewelry seemed to be the best way to interpret the beauty of chaotic shapes.”

At first, the team tried to employ goldsmiths to create prototypes of the twisting, arcing patterns. But the chaotic forms proved too difficult to manufacture with traditional methods. In contrast, additive printing allows for the necessary detail and structure. By 3D-printing the jewelry, the team created a counter-mold for a goldsmith to use as a cast.

“Seeing the chaotic shapes transformed into real, polished, shiny, physical jewelry was a great pleasure for the whole team. Touching and wearing them was also extremely exciting,” said Bilotta. “We think it is the same joy that a scientist feels when her theory takes form, or when an artist finishes a painting.”

The jewelry can also be used as an educational tool, providing students the ability to develop their scientific knowledge and artistic creativity. By building Chua’s circuit, they can manipulate chaos and discover the extreme sensitivity to initial conditions. While designing the jewelry before sending it to be printed, they can tweak the parameters to generate different shapes according to personal taste.

In the future, the authors want to explore representations of chaos using spheres instead of lines. They also plan to create images of chaotic patterns and have developed an exhibition that can be adapted for international museums.               

Here’s a link to and a citation for the paper,

Jewels from chaos: A fascinating journey from abstract forms to physical objects by Francesca Bertacchini, Pietro S. Pantano, and Eleonora Bilotta. Chaos: An Interdisciplinary Journal of Nonlinear Science Volume 33 Issue 1, 013132 (2023) DOI: https://doi.org/10.1063/5.0130029 Published online: 24 January 2023

This paper is behind a paywall.

Insect-inspired microphones

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I was hoping that there would be some insect audio files but this research is more about their role as inspiration for a new type of microphone than the sounds they make themselves. From a May 10, 2023 Acoustical Society of America news release (also on EurekAlert),

What can an insect hear? Surprisingly, quite a lot. Though small and simple, their hearing systems are highly efficient. For example, with a membrane only 2 millimeters across, the desert locust can decompose frequencies comparable to human capability. By understanding how insects perceive sound and using 3D-printing technology to create custom materials, it is possible to develop miniature, bio-inspired microphones.

The displacement of the wax moth Acroia grisella membrane, which is one of the key sources of inspiration for designing miniature, bio-inspired microphones. Credit: Andrew Reid

Andrew Reid of the University of Strathclyde in the U.K. will present his work creating such microphones, which can autonomously collect acoustic data with little power consumption. His presentation, “Unnatural hearing — 3D printing functional polymers as a path to bio-inspired microphone design,” will take place Wednesday, May 10 [2023], at 10:05 a.m. Eastern U.S. in the Northwestern/Ohio State room, as part of the 184th Meeting of the Acoustical Society of America running May 8-12 at the Chicago Marriott Downtown Magnificent Mile Hotel.

“Insect ears are ideal templates for lowering energy and data transmission costs, reducing the size of the sensors, and removing data processing,” said Reid.

Reid’s team takes inspiration from insect ears in multiple ways. On the chemical and structural level, the researchers use 3D-printing technology to fabricate custom materials that mimic insect membranes. These synthetic membranes are highly sensitive and efficient acoustic sensors. Without 3D printing, traditional, silicon-based attempts at bio-inspired microphones lack the flexibility and customization required.

“In images, our microphone looks like any other microphone. The mechanical element is a simple diaphragm, perhaps in a slightly unusual ellipsoid or rectangular shape,” Reid said. “The interesting bits are happening on the microscale, with small variations in thickness and porosity, and on the nanoscale, with variations in material properties such as the compliance and density of the material.”

More than just the material, the entire data collection process is inspired by biological systems. Unlike traditional microphones that collect a range of information, these microphones are designed to detect a specific signal. This streamlined process is similar to how nerve endings detect and transmit signals. The specialization of the sensor enables it to quickly discern triggers without consuming a lot of energy or requiring supervision.

The bio-inspired sensors, with their small size, autonomous function, and low energy consumption, are ideal for applications that are hazardous or hard to reach, including locations embedded in a structure or within the human body.

Bio-inspired 3D-printing techniques can be applied to solve many other challenges, including working on blood-brain barrier organoids or ultrasound structural monitoring.

Here’s a link to and a citation for the paper,

Unnatural hearing—3D printing functional polymers as a path to bio-inspired microphone design by Andrew Reid. J Acoust Soc Am 153, A195 (2023) or JASA (Journal of the Acoustical Sociey of America) Volume 153, Issue 3_supplement March 2023 DOI: https://doi.org/10.1121/10.0018636

You will find the abstract but I wish you good luck with finding the paper online; I wasn’t able and am guessing it’s available on paper only.

3D print healthy chocolates

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I’m a little late for Valentine’s Day, February 14, 2023, but it’s not too late for chocolate.

A February 14, 2023 news item on ScienceDaily describes research into 3D printing ‘healthy’ chocolates,

A Rutgers [Rutgers State University of New Jersey, US] scientist has developed a formulation of low-fat chocolate that can be printed on a 3D printer in pretty much any shape a person can conceive, including a heart.

…

A February 13, 2023 Rutgers University news release (also on EurekAlert but published February 14, 2023) by Kitta MacPherson, which originated the news item, describes research into ‘functional foods’,

The work heralds what the researcher hopes will be a new line of “functional foods” – edibles specially designed with health benefits. The aim is to develop healthier kinds of chocolate easily accessible to consumers.

Reporting in the scientific journal, Food Hydrocolloids, a Rutgers-led team of scientists described the successful creation and printing of a mixture producing low-fat chocolate — substituting fatty cocoa butter with a lower-fat, water-in-oil emulsion.

“Everybody likes to eat chocolate, but we are also concerned with our health,” said Qingrong Huang, a professor in the Department of Food Science at the Rutgers School of Environmental and Biological Sciences. “To address this, we have created a chocolate that is not only low-fat, but that can also be printed with a 3D printer. It’s our first ‘functional’ chocolate.”

Huang, an author of the study, said he already is working on manipulating sugar content in the new chocolate formulation for low-sugar and sugar-free varieties.

Researchers create emulsions by breaking down two immiscible liquids into minute droplets. In emulsions, the two liquids will usually quickly separate – as is the case with oil and vinegar – unless they are held together by a third, stabilizing ingredient known as an emulsifier. (An egg is the emulsifier in a vinaigrette.)

Chocolate candy is generally made with cocoa butter, cocoa powder and powdered sugar and combined with any one of a variety of different emulsifiers.

For the study, the scientific team experimented with different ratios of the ingredients for a standard chocolate recipe to find the best balance between liquid and solid for 3D printing. Seeking to lower the level of fat in the mixture, researchers created a water-in-cocoa butter emulsion held together by gum arabic, an extract from the acacia tree that is commonly used in the food industry, to replace the cocoa butter. The researchers mixed the emulsion with golden syrup to enhance the flavor and added that combination to the other ingredients.

As delightful as it is to eat, Huang said, chocolate is a material rich with aspects for food scientists to explore.

Employing advanced techniques examining the molecular structure and physical properties of chocolate, researchers investigated the printed chocolate’s physical characteristics. They were seeking the proper level of viscosity for printing and looking for the optimal texture and smoothness “for a good mouthfeel,” Huang said. Experimenting with many different water-oil ratios, they varied the percentages of all the main ingredients before settling on one mixture.

In 3D printing, a printer is used to create a physical object from a digital model by laying down layers of material in quick succession. The 3D printer, and the shapes it produces, can be programmed by an app on a cellphone, Huang said.

Ultimately, Huang said he plans to design functional foods containing healthy added ingredients – substances he has spent more than two decades studying, such as extracts from orange peel, tea, red pepper, onion, Rosemary, turmeric, blueberry and ginger – that consumers can print and eat.

“3D food printing technology enables the development of customized edible products with tailored taste, shape and texture as well as optimal nutrition based on consumer needs,” Huang said.

Other researchers on the study included Siqi You and Xuanxuan Lu of the Department of Food Science and Engineering at Jinan University in Guangzhou, China.

Here’s a link to and a citation for the paper,

Development of fat-reduced 3D printed chocolate by substituting cocoa butter with water-in-oil emulsions by Siqi You, Qingrong Huang, and Xuanxuan Lu. Food Hydrocolloids Volume 135, February 2023, 108114 DOI: https://doi.org/10.1016/j.foodhyd.2022.108114

This paper is behind a paywall.

3D-printed ‘smart helmets’ for the military

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Caption: The Rice University-designed smart helmet is intended to modernize standard-issue military helmets by 3D-printing a nanomaterial-enhanced exoskeleton with embedded sensors to actively protect the brain against kinetic or directed-energy effects. Credit: Rice University

Hopefully this will limit the number of head injuries suffered by soldiers.

Some years ago I was at dinner with friends when one of them, a doctor at the local hospital, told me that the Canadian military, which was in Afghanistan at the time, was dealing with a high number of head injury cases, in part due to the soldiers’ own protective gear.

For example, the protective helmet meant you were less likely to receive a catastrophic injury to your cranium (e.g., metal cracking through bone) but your head would be shaken and that isn’t good for anyone’s brain.

It would seem this project at Rice University (Texas, US) is designed to limit the problem of your own protective gear causing injury, from a November 10, 2021 Rice University news release (also on EurekAlert), Note: Links have been removed,

Rice University researchers have received $1.3 million from the Office of Naval Research through the Defense Research University Instrumentation Program to create the world’s first printable military “smart helmet” using industrial-grade 3D printers. 

Led by principal investigator Paul Cherukuri, executive director of Rice’s Institute of Biosciences and Bioengineering, the Smart Helmet program aims to modernize standard-issue military helmets by 3D-printing a nanomaterial-enhanced exoskeleton with embedded sensors to actively protect the brain against kinetic or directed-energy effects. 

Rice will utilize Carbon Inc.’s L1 printer to develop a strong-but-light military-grade helmet that incorporates advances in materials, image processing, artificial intelligence, haptic feedback and energy storage. The printer enables rapid prototyping that in turn simplifies the process of incorporating the sensors, cameras, batteries and wiring harnesses the program requires, Cherukuri said. 

“Current helmets have evolved little since the last century and are still heavy, bulky, passive devices,” he said. “Because of advances in sensors and additive manufacturing, we’re now reimagining the helmet as a 3D-printed, AI-enabled, ‘always-on’ wearable that detects threats near or far and is capable of launching countermeasures to protect soldiers, sailors, airmen and Marines. Essentially, we’re building J.A.R.V.I.S.”

The Smart Helmet program will use technology drawn from projects like the FlatCam, a system developed by co-investigator and electrical and computer engineer Ashok Veeraraghavan and his colleagues that incorporates sophisticated image processing to eliminate the need for bulky lenses, as well as Cherukuri’s Teslaphoresis, a kind of tractor beam for nanomaterials that could help create physical and electromagnetic shields inside the helmets. 

“A smart helmet task force has been assembled from some of the finest minds at Rice to tackle the challenge of creating a self-contained, intelligent system that protects the warfighter at all times,” Cherukuri said. The task force includes the labs of materials scientist Pulickel Ajayan, civil and environmental engineer and Rice Provost Reginald DesRoches, mechanical engineer Marcia O’Malley, chemist James Tour and Veeraraghavan.

While the location of the L1 has yet to be determined, a Carbon M2 printer will be located at the Oshman Engineering Design Kitchen (OEDK), where it will be available for projects other than the helmet. Rice undergraduates who design and build their mandated capstone projects at the OEDK are taking part in the helmet project, working alongside graduate students and postdoctoral researchers to develop the heads-up display.   

“We’ve got a lot of innovative tech in university labs that has never seen the light of day,” Cherukuri said. “We’re simply developing that technology into a device that gives the men and women protecting our country a real chance at coming home safe and sound. This is for them.”

Singapore contributes to art/science gallery on the International Space Station (ISS)

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A March 15, 2022 Nanyang Technological University press release (also on EurekAlert) announces Singapore’s contribution to an art gallery in space,

Two Singapore-designed artefacts are now orbiting around the Earth on the International Space Station (ISS), as part of Moon Gallery.

These artworks were successfully launched into space recently as part of a test flight by the Moon Gallery and will come back to Earth after 10 months.

Currently consisting of 64 artworks made by artists all around the world, the Moon gallery will eventually consist of 100 artworks, which will then be placed on the moon by 2025. Out of these 64 art pieces on the ISS, only two are Singaporean artworks.

…

Here’s Singapore’s contribution,

Caption: NTU [Nanyang Technological University] Singapore Assistant Professor Matteo Seita (left), who is holding the Cube of Interaction, and Ms Lakshmi Mohanbabu (right), who designed both cubes. The Structure & Reflectance cube in the foreground was 3D printed at NTU Singapore.. Credit: NTU Singapore

A December 8, 2021 news item on phys.org describes the project,

The Moon Gallery Foundation is developing an art gallery to be sent to the Moon, contributing to the establishment of the first lunar outpost and permanent museum on Earth’s only natural satellite. The international initiative will see one hundred artworks from artists around the world integrated into a 10 cm x 10 cm x 1 cm grid tray, which will fly to the Moon by 2025. The Moon Gallery aims to expand humanity’s cultural dialog beyond Earth. The gallery will meet the cosmos for the first time in low Earth orbit in 2022 in a test flight.

The test flight is in collaboration with Nanoracks, a private in-space service provider. The gallery is set to fly to the International Space Station (ISS) aboard the NG-17 rocket as part of a Northrop Grumman Cygnus resupply mission in February of 2022. The art projects featured in the gallery will reach the final frontier of human habitat in space, and mark the historical meeting point of the Moon Gallery and the cosmos. Reaching low Earth orbit on the way to the Moon is a pivotal first step in extending our cultural dialog to space.

On its return flight, the Moon Gallery will become a part of the NanoLab technical payload, a module for space research experiments. The character of the gallery will offer a diverse range of materials and behaviors for camera observations and performance tests with NanoLab.

In return, Moon Gallery artists will get a chance to learn about the performance of their artworks in space. The result of these observations will serve as a solid basis for the subsequent Moon Gallery missions and a source of a valuable learning experience for future space artists. The test flight to the ISS is a precursor mission, contributing to the understanding of future possibilities for art in space and strengthening collaboration between the art and space sectors.

…

A December 8, 2021 NYU press release on EurekAlert, which originated the news item, provides more detail about the art from Singapore,

STRUCTURE & REFLECTANCE CUBE

Our every perception, analysis, and thought reflect the influences from our surroundings and the Universe in a world of collaboration, communication and interaction, making it possible to explore the real, the imagined and the unknown. The ‘Structure and Reflectance’ cube, a marriage of Art and Technology, is one of the hundred artworks selected by the Moon Gallery, with a unifying message of an integrated world, making it a quintessential signature of humankind on the Moon.

Ms Lakshmi Mohanbabu, a Singaporean architect and designer, is the first and only local artist to have her artwork selected for the Moon Gallery. Coined the ‘Structure and Reflectance’ cube, Lakshmi’s art is a marriage of Art and Technology and is one of the hundred artworks selected by the Moon Gallery. The cube signifies a unifying message of an integrated world, making it a quintessential signature of humankind on the Moon.

The early-stage prototyping and design iterations of the ‘Structure and Reflectance’ cube were performed with Additive Manufacturing, otherwise known as 3D printing, at Nanyang Technological University, Singapore’s (NTU Singapore)Singapore Centre for 3D Printing (SC3DP). This was part of a collaborative project supported by the National Additive Manufacturing Innovation Cluster (NAMIC), a national programme office which accelerates the adoption and commercialisation of additive manufacturing technologies. Previously, the NTU Singapore team at SC3DP produced a few iterations of Moon-Cube using metal 3D printing in various materials such as Inconel and Stainless Steel to evaluate the best suited material.

The newest iteration of the cube comprises crystals—ingrained in the cube via additive manufacturing technology— revealed to the naked eye by the microscopic differences in their surface roughness, which reflect light along different directions.

“Additive Manufacturing is suitable for enabling this level of control over the crystal structure of solids. More specifically, the work was created using ‘laser powder bed fusion technology’ a metal additive manufacturing process which allows us to control the surface roughness through varying the laser parameter,” said Dr Matteo Seita, Nanyang Assistant Professor, NTU Singapore, is the Principal Investigator overseeing the project for the current cube design.  

Dr Seita shared the meaning behind the materials used, “Like people, materials have a complex ‘structure’ resulting from their history—the sequence of processes that have shaped their constituent parts—which underpins their differences. Masked by an exterior façade, this structure often reveals little of the underlying quality in materials or people. The cube is a material representation of a human’s complex structure embodied in a block of metal consisting of two crystals with distinct reflectivity and complementary shape.”

Ms Lakshmi added, “The optical contrast on the cube surface from the crystals generates an intricate geometry which signifies the duality of man: the complexity of hidden thought and expressed emotion. This duality is reflected by the surface of the Moon where one side remains in plain sight, while the other has remained hidden to humankind for centuries; until space travel finally allowed humanity to gaze upon it. The bright portion of the visible side of the Moon is dependent on the Moon’s position relative to the Earth and the Sun. Thus, what we see is a function of our viewpoint.”

The hidden structure of materials, people, and the Moon are visualized as reflections of light through art and science in this cube. Expressed in the Structure & Reflectance cube is the concept of human’s duality—represented by two crystals with different reflectance—which appears to the observer as a function of their perspective.

Dr Ho Chaw Sing, Co-Founder and Managing Director of NAMIC said, “Space is humanity’s next frontier. Being the only Singaporean – among a selected few from the global community – Lakshmi’s 3D printed cube presents a unique perspective through the fusion of art and technology. We are proud to have played a small role supporting her in this ‘moon-shot’ initiative.”

Lakshmi views each artwork as a portrayal of humanity’s quests to discover the secrets of the Universe and—fused into a single cube—embody the unity of humankind, which transcends our differences in culture, religion, and social status.

The first cube face, the Primary, is divided into two triangles and depicts the two faces of the Moon, one visible to us from the earth and the other hidden from our view.

The second cube face, the Windmill, has two spiralling windmill forms, one clockwise and the other counter-clockwise, representing our existence, energy, and time.

The third cube face, the Dromenon, is a labyrinth form of nested squares, which represents the layers that we—as space explorers—are unravelling to discover the enigma of the Universe. 

The fourth cube face, the Nautilus, reflects the spiralling form of our DNA that makes each of us unique, a shape reflected in the form of our galaxy.

Not having heard of the Moon Gallery or the Moon Gallery Foundation, I did a little research. There’s a LinkedIn profile for the Moon Gallery Foundation (both the foundation and the gallery are located in Holland [Netherlands]),

Moon Gallery is where art and space meet. We aim to set up the first permanent museum on the Moon and develop a culture for future interplanetary society.

Moon Gallery will launch 100 artefacts to the Moon within the compact format of 10 x 10 x 1cm plate on a lunar lander exterior panelling no later than 2025. We suggest bringing this collection of ideas as the seeds of a new culture. We believe that culture makes a distinction between mere survival and life. Moon Gallery is a symbolic gesture that has a real influence – a way to reboot culture, rethink our values for better living on Earth planet.

…

The Moon Gallery has its own website, where I found more information about events, artists, and partners such as Nanoracks,

Nanoracks is dedicated to using our unique expertise to solve key problems both in space and on the Earth – all while lowering the barriers to entry of space exploration. Nanoracks’s main office is in Houston, Texas. The business development office is in Washington, D.C., and additional offices are located in Abu Dhabi, United Arab Emirates (UAE) and Turin, Italy. Nanoracks provides tools, hardware and services that allow other companies, organizations and governments to conduct research and other projects in space. Some of Nanoracks customers include Student Spaceflight Experiments Program (SSEP), the European Space Agency (ESA), the German Space Agency (DLR), NASA, Planet Labs, Space Florida, Virgin Galactic, Adidas, Aerospace Corporation, National Reconnaissance Office (NRO), UAE Space Agency, Mohammed bin Rashid Space Centre (MBRSC), and the Beijing Institute of Technology.

You can find the Nanoracks website here.