Making 3D printing truly 3D - Today's Medical Developments

2022-05-28 02:25:15 By : Ms. yoyo zheng

Harvard University's Rowland Institute researchers eliminate the need for 2D layering.

Don’t be fooled by the name. While 3D printers do print tangible objects (and quite well), how they do the job doesn’t actually happen in 3D, but rather in regular old 2D.

Working to change that is a group of former and current researchers from the Rowland Institute at Harvard.

First, here’s how 3D printing works: The printers lay down flat layers of resin, which will harden into plastic after being exposed to laser light, on top of each other, again and again from the bottom to the top. Eventually, the object, such as a skull, takes shape. But if a piece of the print overhangs, like a bridge or a wing of a plane, it requires some type of flat support structure to actually print, or the resin will fall apart.

The researchers present a method to help the printers live up to their names and deliver a “true” 3D form of printing. In a new paper in Nature, they describe a technique of volumetric 3D printing that goes beyond the bottom-up, layered approach. The process eliminates the need for support structures because the resin it creates is self-supporting.

“What we were wondering is, could we actually print entire volumes without needing to do all these complicated steps?” said Daniel N. Congreve, an assistant professor at Stanford and former fellow at the Rowland Institute, where the bulk of the research took place. “Our goal was to use simply a laser moving around to truly pattern in three dimensions and not be limited by this sort of layer-by-layer nature of things.”

The key component in their novel design is turning red light into blue light by adding what’s known as an up-conversion process to the resin, the light reactive liquid used in 3D printers that hardens into plastic.

In 3D printing, resin hardens in a flat and straight line along the path of the light. Here, the researchers use nano capsules to add chemicals so that it only reacts to a certain kind of light – a blue light at the focal point of the laser that’s created by the up-conversion process. This beam is scanned in three dimensions, so it prints that way without needing to be layered onto something. The resulting resin has a greater viscosity than in the traditional method, so it can stand support-free once it’s printed.

“We designed the resin, we designed the system so that the red light does nothing,” Congreve says. “But that little dot of blue light triggers a chemical reaction that makes the resin harden and turn into plastic. Basically, what that means is you have this laser passing all the way through the system and only at that little blue do you get the polymerization, [only there] do you get the printing happening. We just scan that blue dot around in three dimensions and anywhere that blue dot hits it polymerizes and you get your 3D printing.”

The researchers used their printer to produce a 3D Harvard logo, Stanford logo, and a small boat, a standard yet difficult test for 3D printers because of the boat’s small size and fine details like overhanging portholes and open cabin spaces.

The researchers, who included Christopher Stokes from the Rowland Institute, plan to continue developing the system for speed and to refine it to print even finer details. The potential of volumetric 3D printing is seen as a game changer, because it will eliminate the need for complex support structures and dramatically speed up the process when it reaches its full potential. Think of the “replicator” from “Star Trek” that materializes objects all at once.

But right now, the researchers know they have quite a ways to go.

“We’re really just starting to scratch the surface of what this new technique could do,” Congreve says.

Boston University–led team engineered a tiny living heart chamber replica to mimic the real organ more accurately, provide a sandbox for testing new heart disease treatments.

There’s no safe way to get a close-up view of the human heart as it goes about its work: you can’t just pop it out, take a look, then slot it back in. Scientists have tried different ways to get around this fundamental problem: they’ve hooked up cadaver hearts to machines to make them pump again, attached lab-grown heart tissues to springs to watch them expand and contract. Each approach has its flaws: reanimated hearts can only beat for a few hours; springs can’t replicate the forces at work on the real muscle. But getting a better understanding of this vital organ is urgent: in America, someone dies of heart disease every 36 seconds, according to the Centers for Disease Control and Prevention.

Now, an interdisciplinary team of engineers, biologists, and geneticists has developed a new way of studying the heart: they’ve built a miniature replica of a heart chamber from a combination of nanoengineered parts and human heart tissue. There are no springs or external power sources – like the real thing, it just beats by itself, driven by the live heart tissue grown from stem cells. The device could give researchers a more accurate view of how the organ works, allowing them to track how the heart grows in the embryo, study the impact of disease, and test the potential effectiveness and side effects of new treatments – all at zero risk to patients and without leaving a lab.

The Boston University–led team behind the gadget – nicknamed miniPUMP, and officially known as the cardiac miniaturized Precision-enabled Unidirectional Microfluidic Pump – says the technology could also pave the way for building lab-based versions of other organs, from lungs to kidneys. Their findings have been published in Science Advances.

“We can study disease progression in a way that hasn’t been possible before,” says Alice White, a BU College of Engineering professor and chair of mechanical engineering. “We chose to work on heart tissue because of its particularly complicated mechanics, but we showed that, when you take nanotechnology and marry it with tissue engineering, there’s potential for replicating this for multiple organs.”

According to the researchers, the device could eventually speed up the drug development process, making it faster and cheaper. Instead of spending millions – and possibly decades – moving a medicinal drug through the development pipeline only to see it fall at the final hurdle when tested in people, researchers could use the miniPUMP at the outset to better predict success or failure.

The project is part of CELL-MET, a multi-institutional National Science Foundation Engineering Research Center in Cellular Metamaterials that’s led by BU. The center’s goal is to regenerate diseased human heart tissue, building a community of scientists and industry experts to test new drugs and create artificial implantable patches for hearts damaged by heart attacks or disease.

“Heart disease is the number one cause of death in the United States, touching all of us,” says White, who was chief scientist at Alcatel-Lucent Bell Labs before joining BU in 2013. “Today, there is no cure for a heart attack. The vision of CELL-MET is to change this.”

Personalized medicine There’s a lot that can go wrong with your heart. When it’s firing properly on all four cylinders, the heart’s two top and two bottom chambers keep your blood flowing so that oxygen-rich blood circulates and feeds your body. But when disease strikes, the arteries that carry blood away from your heart can narrow or become blocked, valves can leak or malfunction, the heart muscle can thin or thicken, or electrical signals can short, causing too many – or too few – beats. Unchecked, heart disease can lead to discomfort – like breathlessness, fatigue, swelling, and chest pain – and, for many, death.

“The heart experiences complex forces as it pumps blood through our bodies,” says Christopher Chen, BU’s William F. Warren Distinguished Professor of Biomedical Engineering. “And while we know that heart muscle changes for the worse in response to abnormal forces – for example, due to high blood pressure or valve disease – it has been difficult to mimic and study these disease processes. This is why we wanted to build a miniaturized heart chamber.”

At just 3 square centimeters, the miniPUMP isn’t much bigger than a postage stamp. Built to act like a human heart ventricle – or muscular lower chamber – its custom-made components are fitted onto a thin piece of 3D-printed plastic. There are miniature acrylic valves, opening and closing to control the flow of liquid – water, in this case, rather than blood – and small tubes, funneling that fluid just like arteries and veins. And beating away in one corner, the muscle cells that make heart tissue contract, cardiomyocytes, made using stem cell technology.

“They’re generated using induced pluripotent stem cells,” says Christos Michas (ENG’21), a postdoctoral researcher who designed and led the development of the miniPUMP as part of his PhD thesis.

To make the cardiomyocyte, researchers take a cell from an adult – it could be a skin cell, blood cell, or just about any other cell – reprogram it into an embryonic-like stem cell, then transform that into the heart cell. In addition to giving the device literal heart, Michas says the cardiomyocytes also give the system enormous potential in helping pioneer personalized medicines. Researchers could place a diseased tissue in the device, for instance, then test a drug on that tissue and watch to see how its pumping ability is impacted.

“With this system, if I take cells from you, I can see how the drug would react in you, because these are your cells,” Michas says. “This system replicates better some of the function of the heart, but at the same time, gives us the flexibility of having different humans that it replicates. It’s a more predictive model to see what would happen in humans – without actually getting into humans.”

According to Michas, that could allow scientists to assess a new heart disease drug’s chances of success long before heading into clinical trials. Many drug candidates fail because of their adverse side effects.

“At the very beginning, when we’re still playing with cells, we can introduce these devices and have more accurate predictions of what will happen in clinical trials,” Michas says. “It will also mean that the drugs might have fewer side effects.”

Thinner than a human hair One of the key parts of the miniPUMP is an acrylic scaffold that supports, and moves with, the heart tissue as it contracts. A series of superfine concentric spirals – thinner than a human hair – connected by horizontal rings, the scaffold looks like an artsy piston. It’s an essential piece of the puzzle, giving structure to the heart cells – which would just be a formless blob without it – but not exerting any active force on them.

“We don’t think previous methods of studying heart tissue capture the way the muscle would respond in your body,” says Chen, who’s also director of BU’s Biological Design Center and an associate faculty member at Harvard University’s Wyss Institute for Biologically Inspired Engineering. “This gives us the first opportunity to build something that mechanically is more similar to what we think the heart is actually experiencing – it’s a big step forward.”

To print each of the tiny components, the team used a process called two-photon direct laser writing – a more precise version of 3D printing. When light is beamed into a liquid resin, the areas it touches turn solid; because the light can be aimed with such accuracy – focused to a tiny spot – many of the components in the miniPUMP are measured in microns, smaller than a dust particle.

The decision to make the pump so small, rather than life-size or larger, was deliberate and is crucial to its functioning.

“The structural elements are so fine that things that would ordinarily be stiff are flexible,” White says. “By analogy, think about optical fiber: a glass window is very stiff, but you can wrap a glass optical fiber around your finger. Acrylic can be very stiff, but at the scale involved in the miniPUMP, the acrylic scaffold is able to be compressed by the beating cardiomyocytes.”

Chen says that the pump’s scale shows “that with finer printing architectures, you might be able to create more complex organizations of cells than we thought was possible before.” At the moment, when researchers try to create cells, he says, whether heart cells or liver cells, they’re all disorganized – “to get structure, you have to cross your fingers and hope the cells create something.” That means the tissue scaffolding pioneered in the miniPUMP has big potential implications beyond the heart, laying the foundation for other organs-on-a-chip, from kidneys to lungs.

Refining the technology According to White, the breakthrough is possible because of the range of experts on CELL-MET’s research team, which included not just mechanical, biomedical, and materials engineers like her, Chen, and Refining the Technology, but also geneticist Jonathan G. Seidman of Harvard Medical School and cardiovascular medicine specialist Christine E. Seidman of Harvard Medical School and Brigham and Women’s Hospital. It’s a breadth of experience that’s benefited not just the project, but Michas. An electrical and computer engineering student as an undergraduate, he says he’d “never seen cells in my life before starting this project.”

Now, he’s preparing to start a new position with Seattle-based biotech Curi Bio, a company that combines stem cell technology, tissue biosystems, and artificial intelligence to power the development of drugs and therapeutics.

“Christos is someone who understands the biology,” White says, “can do the cell differentiation and tissue manipulation, but also understands nanotechnology and what’s required, in an engineering way, to fabricate the structure.”

The next immediate goal for the miniPUMP team? To refine the technology. They also plan to test ways to manufacture the device without compromising its reliability.

“There are so many research applications,” Chen says. “In addition to giving us access to human heart muscle for studying disease and pathology, this work paves the way to making heart patches that could ultimately be for someone who had a defect in their current heart.”

Other researchers on this project included Kamil Ekinci, a BU College of Engineering (ENG) professor of mechanical engineering and materials science and engineering, Jeroen Eyckmans, an ENG research assistant professor of biomedical engineering, M. Çagatay Karakan (ENG’22), and Pranjal Nautiyal, a postdoctoral researcher at the ??University of Pennsylvania who recently completed his PhD at Florida International University.

Purdue-related startup Araqev has developed software to print products in only a few design iterations, leading to less scrap and less machining time.

Aerospace, automotive, consumer products, medical devices, national defense, and other sectors that use additive manufacturing (AM) and 3D printing (3DP) technologies could benefit from quality-control software commercialized by Araqev, a Purdue University-related company.

Araqev's software helps end users print products in only a few design iterations, leading to less scrap material and machining time, eliminating the frustrations with 3DP, and improving satisfaction with the final printed products. Arman Sabbaghi, associate professor in Purdue's Department of Statistics in the College of Science, is Araqev's CEO and president.

"We estimate that the quality-control issue with AM can lead to nearly $2 billion in global losses annually based on a model for the production costs of metal AM systems that was developed by Baumers, Dickens, Tuck, and Hague in their 2016 paper published in the peer-reviewed journal Technological Forecasting and Social Change," Sabbaghi says.

To use Araqev's software, customers upload their nominal design files and scanned point cloud data from their printed products.

"Our software uses these inputs to fit machine learning models that can simulate shape deviations for future printed products," Sabbaghi says. "Furthermore, the machine learning (ML) models enable our software to derive modifications to the nominal designs, known as compensation plans, so that when the modified designs are printed, they will exhibit fewer shape deviations compared to the case when the original designs are printed."

Araqev's algorithms also enable the transfer of knowledge encoded via ML models across different materials, printers, and shapes in an AM system.

"This means that our software enables a comprehensive platform for a customer to improve quality for their entire system," Sabbaghi says.

"The power and cost-effectiveness of our algorithms were most recently demonstrated via two validation experiments for the Markforged Metal X 3D printer involving 17-4 PH stainless steel products," Sabbaghi says. "Our algorithms reduced shape inaccuracies by 30% to 60%, depending on the geometry in at most two iterations, with three training shapes and one or two test shapes for a specific geometry involved across the iterations."

Araqev is establishing direct partnerships with 3DP manufacturers and companies using 3D printers that Sabbaghi says will enable the company to scale quickly.

"We will establish licensing contracts after demonstrating to the companies the savings and benefits that we can offer for their processes," Sabbaghi says. "These partners will incorporate our software into their systems and sell them to their customers, which provides us with a significant customer channel."

Araqev licensed the software from the Purdue Research Foundation Office of Technology Commercialization. The research to create the software received funding from the NSF's Cyber-Physical Systems program and CMMI EAGER program, and the Purdue Research Foundation Office of Technology Commercialization's Trask Innovation Fund. Araqev received funds from Elevate Ventures' Regional Pre-Seed Competition (https://elevateventures.com/elevate-ventures-invests-660k-in-15-companies), Purdue's Regional NSF I-Corps program, the MKE Tech Hub Coalition Challenge and the Purdue Foundry Boost program.

CNC Software LLC establishes Mastercam UK upon closing of 4D Engineering Ltd.

CNC Software LLC, the developers of Mastercam, announced that with the closing of reseller, 4D Engineering Ltd., the United Kingdom region will now be supported by the new business entity, Mastercam UK.

4D Engineering Ltd, headquartered in Cirencester, United Kingdom, announced that after supporting the Mastercam community for 32 years, it would cease operations as of March 23, 2022.

Due to the unique nature of this transition, Mastercam Corporate will now provide industry-leading support and resources for users in the United Kingdom under the name Mastercam UK.

Mastercam UK will be independently and locally operated as a member of the global Mastercam Reseller network.

President and CEO of CNC Software, LLC, Meghan West shares, “This is an exciting move for us here at Mastercam because it allows us to transition existing business by 4D Engineering into our new entity and also gives us the opportunity to expand and grow in the UK.”

New Texas production and distribution site – a 285,000 sq. ft. facility – will double production capacity upon opening.

Methods Machine Tools, the foremost supplier of high-quality, high-precision CNC machine tools and automation in North America, will open a state-of-the-art production and distribution center in Fort Worth, Texas.

Scheduled to open in February 2023, the 285,000ft2 facility will serve as a flagship production, engineering, and logistics hub from which Methods will continue to aggressively scale its North America business. Additionally, the site will host leading-edge innovation programs conducted by Methods’ engineering, applications, and automation experts, dedicated training areas, and a showcase technical center.

“This is a momentous day for Methods Machine Tools. Our Texas hub is a foundational piece of our national expansion strategy,” says Mark Wright, Methods president and CEO. “For the most sophisticated manufacturing across all verticals, our new facility will uniquely position us to better serve our customers throughout the greater Southwest, Pacific Coast regions, and Mexico.

“Our customers and our growing dealer network want more of our automation solutions and unmatched machine tools,” Wright continues. “With proximity to Houston’s deep-water port and excellent access to highways systems, we will strengthen our national supply chain to rapidly fulfill our increasing demand.”

Methods expanded into Texas in late 2021 upon completing its acquisition of Houston- and Dallas-based Koch Machine Tool, shortly followed by recent expansion in the Midwest.

“While thinking about what this expansion means for Methods’ future, I first go back to my grandfather and our founder Clement McIver, Sr.,” says Methods owner and chairman Scott McIver. “Decades ago, he envisioned Texas one day becoming a central location to support our long-term growth. Today, on behalf of my family, I’m humbled and proud to see his vision become reality.”

Methods is hiring at its current Texas locations with more roles to be added before and after the Fort Worth opening, while hiring continues at its 11 other locations coast to coast.