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MIT Researchers Create Reprogrammable Color-Changing Dyes

How many times have you purchased the same item, but in different colors? Those new Adidas are definitely rad with red stripes, but sometimes a nice blue would suit your outfit better. That flower print phone case your mom bought you protects your phone well, but maybe you’d prefer something a bit more modern. To avoid having to buy multiple colors of a single item — or throw away outdated designs — researchers from MIT’s CSAIL (Computer Science and Artificial Intelligence Laboratory) have developed a new reprogrammable color-changing dye.

This dye, called PhotoChromeleon, builds on a previous project that allowed 3D-printed objects to change color. During the 3D-printing process, the plastic was filled with special photochromic dyes. Those react to UV light to change from transparent to a specific color. The problem with that technique was that each “pixel” had to be dyed separately for each color, resulting in a grainy pattern. It also only worked with 3D-printed objects. PhotoChromeleon address both issues, as it can be applied to any object and the doesn’t needed to be separated by color.

To achieve that, PhotoChromeleon mixes three photochromic dyes that change color when exposed to a specific wavelength of light. Those colors are cyan, magenta, and yellow, and each one responds to a different wavelength. The PhotoChromeleon mixture can be sprayed onto anything from a pair of shoes to a car, and exposed to UV light to fully saturate all three colors. Then a projector is used to “turn off” each dye color in specific patterns. The entire object’s color can be changed, or detailed designs can be projected. That process can be repeated over and over whenever a change is desired. The research team even developed a software interface that makes it easy to control the projector and create a design. Now they want to collaborate with material scientists to create new dyes with a better range of colors.

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Author: Cameron Coward

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Lollies, vitamins and fish-shaped sauce containers hit the MRI mark

For children fearful of undergoing MRI scans, an inexpensive everyday item used as a marker, such as a jelly baby lolly or a plastic, fish-shaped soy sauce container, might make the process a little less intimidating.

And thanks to a QUT study, these and other relatively cheap, common items have been shown to be visible, effective MRI markers, when placed on a patient’s skin, to pinpoint specific anatomical areas or pathologies being scanned.

The study findings have been published in the British Medical Journal’s BMJ Open.

Senior Research Fellow Dr Paige Little, from the QUT Biomechanics and Spine Research Group, said MRI uses strong magnetic fields to generate images of organs, bone and tissue inside the body and the loud noises made by the equipment adds to the challenges radiographers face to perform MRI scans successfully on children.

She said the impetus for looking at alternatives to commercial markers was the group’s collaborative sleep postures research project.

“Single-use commercial markers cost between $6 and $10 each, and for our sleep posture study we had 50 participants, and we needed 50 markers for each participant, which made the cost prohibitive,” Dr Little said.

“We needed to find a marker that was small, inexpensive and easily sourced, which showed up clearly on MRI and was easily distinguishable from bone and soft tissue.

“While makeshift markers of various types, including fish oil capsules, have been anecdotally trialled in clinical radiology departments over the years, we couldn’t find a study in the scientific literature, so we did our own trial.

“We tested 17 items, including different lollies, a coffee bean, vitamin tablets and capsules, and the capped fish-shaped soy sauce containers that you can get when you buy sushi.”

Dr Little said all the alternative markers, plus a commercial product for comparison, were tested on the thigh of a member of the research team, and scanned at Mater Medical Imaging using the five most commonly ordered MRI sequences.

“The visibility of some of the items, like the coffee bean, was poor, but overall we found the vitamin D capsule proved to be the best substitute for a commercial marker for all tests, and particularly good for smaller areas of the body like fingers and toes,” Dr Little said.

“The jelly baby lolly, fish-shaped sauce container, and the fish oil capsule were also viable alternatives for some, although not all, of the MRI sequences.

“Our conclusion was that depending on the reason for imaging and the sequence selected, these four items were cheap and reliable alternatives to a commercial marker.

“Single-use markers are a significant component of an imaging department’s costs, and also for researchers, so we thought this study was a practical examination of viable alternatives.

“And if using something familiar would help make the imaging process less frightening for children, particularly those children who have experienced many medical procedures, then that is a terrific bonus.”

Dr Little said while the study didn’t test at what point a vitamin capsule or sauce container might rupture and spill its contents, the research group has since used vitamin D capsules routinely in spinal studies, and in its Sealy of Australia-supported ‘Science of Sleep’ postures project, requiring multiple markers under body weight throughout extended MRI scanning sessions, and none had ruptured or degraded.

Co-authors with Dr Little of the BMJ Open study are Mrs Maree Izatt, Dr Caroline Grant, and Dr Deborah Lees from the QUT Biomechanics and Spine Research Group, and Ms Susan Mills from Mater Medical Imaging.

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Unraveling the history and science behind ancient decorative metal threads

When it comes to historical fashion, nothing stands out more than an item woven with shiny metal threads. These threads have been woven into textiles since ancient times and have been used by cultures around the world. However, the historical record has limited insight into how these materials were made, and conservation efforts limit scientists’ ability to obtain samples because many methods are destructive. Today, researchers report their progress toward a new, less damaging methodology for analyzing metal threads.

The researchers will present their results at the American Chemical Society (ACS) Fall 2019 National Meeting & Exposition.

“This project began when we were asked to investigate the metal threads of a 14th century Italian textile using a proteomics-based approach,” says Caroline Solazzo, Ph.D., who is one of the project’s principal investigators. Her team published a study last year characterizing the protein-containing membranes and adhesives in the threads of this artifact, which were made from animal products such as cow hide and pig intestine. Now, the team is reporting on their investigation into the exact composition of metal fibers of this and other historical objects.

“Conservation science is a unique area of chemistry research,” says Aleksandra Popowich, Ph.D., who is presenting the work at the meeting. “We are using microscopy techniques that allow us to build a 3D view of the threads, so we can see things like layering and micro-structure that give us insight into when and how the fibers were made.” Both Solazzo and Popowich are researchers at the Smithsonian’s Museum Conservation Institute, a center for specialized technical collections research and conservation of artistic, anthropological, biological and historical artifacts.

While decorative metal threads have been a subject of historical research interest for decades, studies to determine their manufacture and makeup have relied on cross-section analysis to view the internal metal structure. The current study, however, was driven by the desire to maintain the integrity of artifacts.

For this particular work, Popowich and her Smithsonian colleagues Thomas Lam, Ph.D., and Edward Vicenzi, Ph.D., obtained 30 samples from the Fashion Institute of Technology. The samples originated from Europe, Asia and the Middle East, and some of them were nearly 1,000 years old. The types of threads were diverse; some were strips of metal, others were strips of paper wrapped around fibers. Many of the pieces were religious textiles, such as vestments, demonstrating the cultural and historical importance of metal threadwork.

To get a closer look, the researchers developed a strategy that combined energy dispersive X-ray spectroscopy and correlated micro X-ray fluorescence. Together, the methods provided a high-resolution map of the threads’ elemental composition and thickness. These techniques only required a few micrograms of material, leaving most of the threads intact for future conservation efforts.

The resulting surface images and cross-sections showed that most threads had a combination of gold, silver and sometimes copper or zinc, creating a layered structure that highlighted the intricacy of the craftsmanship. The researchers learned that some thread-making techniques vary by culture, but other methods did not change much over time. For example, data from two French threads, one from the 16th century and one from the 18th century, showed that the process of rolling super-thin metal wires and wrapping them around a core material was largely unchanged between those years. In addition, the measurements taken using this method align with historic sources and data from computer simulations.

With this pilot investigation completed, the researchers plan to further develop this strategy to the point where they do not need to destroy a piece of the sample at all. This advance could open up the list of artifacts for study to include those that are too culturally important to damage for the sake of research. Such a method could also expand their work to include other materials, such as gilt leather, tapestries or gilded furniture.

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Materials provided by American Chemical Society. Note: Content may be edited for style and length.

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This Animatronic Eye of Agamotto Was 3D-Printed in Amazing Detail

In the Marvel Cinematic Universe, the Eye of Agamotto is a powerful and mystical item that contains the Time Stone — one of the six Infinity Stones that Thanos collected for his gauntlet. The Eye of Agamotto resides within an amulet worn by Doctor Strange. The comic books featured many different variations of the Eye of Agamotto, but the way it was depicted in the MCU movies was particularly iconic. Instagrammer ezbsvs has brought that design to life using high-quality 3D-printing and animatronics.

The amulet, as shown in the modern MCU movies, contains the Eye of Agamotto locked within a small chamber and surrounded by complex spinning mechanisms. Amazingly, ezbsvs was able to recreate that intricate movement, with a design featuring concentric rings each turning in opposite directions and then opening the “eyelid” to expose the Eye of Agamotto. That required brilliant engineering work to design the mechanisms and gears in Autodesk Fusion 360 CAD (Computer-Aided Design) software.

After designing those parts, ezbsvs sent them off to Shapeways to be 3D-printed using the MultiJet printing process, which is ideal for parts with a lot of fine details. That was necessary to ensure that the gears meshed smoothly. The rings are spun by six 700:1 plastic gearmotors, and the eyelid is opened and closed with a 1000:1 metal gearmotor. All of those are powered through Pololu motor drivers, and controlled by an Arduino Nano. The Arduino also controls the LEDs inside of the actual eye. With the addition of a masterful paint job, the amulet and Eye of Agamotto look as good as what Doctor Strange wears in the movies.

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Author: Cameron Coward