Stronger, Lighter, Cheaper

By Catherine

Written by Catherine Bolgar*
NanomaterialIndustrial materials involve trade-offs. Desirable qualities tend to come with undesirable flip sides. Strength, for example, tends to come at the expense of ductility, or the ability to stretch without breaking. So the stronger something is, the more it’s likely—ironically—that when it does fail, it fails completely.

What if you could have both high strength and ductility? This is likely to happen, thanks to breakthroughs in new materials, many of which involve building the materials in innovative ways at the atomic level.

A microscopic view of metals would show them as made up of grains. Stronger materials have smaller grains, and more ductile materials have larger grains, explains Yuntian Zhu, professor of materials science and engineering at North Carolina State University in the U.S. However, if you make an entire part with small grains for high strength, it might fail catastrophically under stress.

When you make any structure, you want at least 5% ductility. The more ductility, the safer it is. But the downside is that the strength comes down,” he says.

Dr. Zhu found that by forming steel with larger grains inside and gradually moving to smaller grains at the surface, the result has both strength and ductility. This gradient structure is found in nature, he says, for example in plants and bones.

Near the surface, it’s harder. As you go deeper it gets softer,” Dr. Zhu says. “Nature just puts raw materials where they’re needed most. It minimizes the material cost. In nature, that proves useful.”

Using a gradient structure in steel could extend the lives of bridges, ships and oil pipelines, for instance.

Hardening steel by working it is another technique to make steel that’s both strong and ductile. Twinning-induced plasticity—or TWIP—steel is strengthened by twisting, deforming, bending, flattening or hammering it. At Brown University, researchers twisted cylinders of TWIP steel to deform the molecules on the surface. The molecules in the center remained unaffected, providing the flexibility, while the surface got harder, providing more strength.

Usually when something is strong, it’s also heavy. What if you could have both strength and lightness?

Nicholas X. Fang, associate professor of mechanical engineering at the Massachusetts Institute of Technology, has developed a foam material that can withstand a weight 10,000 times greater than its own.

“It’s as light as aerogel, yet as stiff as a hammer,” he says. Much of the space between the structures is void, which is why the material is so light.

The material uses nanotubes or nanowires a quarter of the size of a human hair to form a network or structure that takes away the load. “Each of the nanotubes under the load are under compression or a stress state,” Dr. Fang says. “But they turn out to be quite resilient. In the lab, we compress the samples to 60% of their original size.”

Dr. Fang is contemplating applications for this new material. The material could absorb impact while reducing weight, for example, in a tennis racket that’s lighter than aluminum alloy, yet able to deliver similar strength against a bouncing ball.

It could be important for microstructures in batteries,” he adds. Batteries receive a lot of shock when charging, which causes the structure to suddenly expand—and corrode. “If we could use this material in a battery, we could solve the challenge of quick charging,” he says.

Satellites also could benefit from a material that’s very lightweight, to reduce the payload, yet able to withstand shocks.

Nanowires in three-dimensional structures also are being explored by researchers at the University of California, Davis. By combining atoms of semiconductor materials—such as gallium arsenide, gallium nitride or indium phosphide—into nanowires that form structures on top of silicon surfaces, they hope to create a new generation of fast electronic and photonic devices.

The nanowire transistors could be used to make sensors that can withstand high temperatures and are easier to cool.

polymer surfaceSomething everybody wants to be strong yet shatterproof is their smartphone screen. Researchers at the University of Akron in Ohio have come up with a transparent layer of electrodes on a polymer surface that could stand up to repeatedly having adhesive tape peeled off and retain its shape after being bent a thousand times. The new film may be cheaper to make than the coatings of indium tin oxide now used on smartphone screens.

In fact, in a number of cases, the materials or processes themselves aren’t necessarily expensive, which makes them likely to be adopted relatively quickly.

It’s actually quite easy,” says Dr. Zhu about making steel with a gradient structure. “The only thing is, can we do it in an industrial way or develop a technology to do it?” The cost is likely to be very low, and some in industry already are trying it.

“It might take a few years for widespread adoption,” he says.

The super-strong foam material developed by Dr. Fang isn’t expensive, but the manufacturing process is—at least for now. Only a few centimeters of the material can be made, which is a limitation of the printing process, not the material itself, Dr. Fang says. “Now it’s important to connect the dots to make it into a larger format at lower cost.”

*For more from Catherine, contributors from the Economist Intelligence Unit along with industry experts, join The Future Realities discussion.

Medical engineering’s future frontiers

By Catherine

By Catherine Bolgar*

Future technology to detect and treat diseases is coming from some surprising sources. We talk about “fighting diseases” or “fighting cancer,” for example. Well, how about using military technology for medical devices?

medical device

MelaFind, which is already on the market, uses innovative spectral imaging and software-driven technology born from missile-navigation systems to help dermatologists detect melanoma at its most treatable stage.

Melanoma accounts for only 5% of all skin cancers but is responsible for 75% of deaths. Caught early it’s almost 100% curable; however, by the time melanoma goes more than 1mm below the skin, patients have a 50% chance of dying, usually within a year.

“Dermatologists are probably the last group of physicians who don’t use imaging as a standard,” says Rose Crane, chief executive and president of MELA Sciences, the Irvington, New York, company that makes MelaFind. While dermatologists are very good at spotting melanoma vs. benign moles, many cases are difficult and ambiguous for them, she says.

MelaFind uses spectral light to illuminate the skin, and then provides the doctor with 3D images, as with magnetic resonance imaging. Then, the images are analyzed with proprietary algorithms that provide the doctor with data on the probability of the lesion being a melanoma based on the largest positive, prospective study ever conducted on the disease.

It’s able to non-invasively image and analyze irregular moles 2.5mm below the skin surface where a doctor can’t see unless he/she cuts,” she says.

Near-Infrared Fluorescence Lymphatic Imaging (NIRF-LI) is another device that uses military technology for medical imaging. NIRF-LI stands for “near-infrared fluorescence lymphatic imaging,” and uses infrared military-grade night-vision technology to see the body’s lymphatic structures and flow for the first time.

Watching television coverage of nighttime operations during the first Gulf War, Eva Sevick-Muraca, now professor of molecular medicine at the University of Texas Health Science Center at Houston, or UTHealth, recalls that she “had the crazy idea that we could use near-infrared fluorescence for medical imaging. We don’t have any natural molecules in the body that fluoresce at these wavelengths, but if we could find a molecule that does and use it as a contrast agent, we could use harmless light for medical imaging.”

Indocyanine green, or ICG, fluoresces when illuminated with near-infrared light. Once a tiny amount of ICG is injected into the skin, the lymphatics draw the dye into the lymphatic vessels, through regional lymph nodes and beyond. When dim laser light illuminates tissue surfaces, the dye “lights” up, and NIRF-LI enables visualization of the ICG moving through the lymphatics, explains John Rasmussen, assistant professor at UTHealth. NIRF-LI can take pictures of this so quickly that it can image actual lymphatic flow.

The device is important because the lymphatics play a role in many diseases and conditions that are becoming more prevalent, including cancer, lymphedema, autoimmune diseases, asthma, chronic wounds, vascular disease and others.

Doctors typically check lymph nodes for cancer when removing tumors, but lymph nodes aren’t in exactly the same places in each person, so surgeons have to hunt for them. Once found, the lymph nodes are removed for biopsy to see whether they are cancerous. Eventually, using cancer-targeted imaging agents, NIRF-LI could be used for “image-guided lymph node dissection,” says Dr. Sevick, to determine whether they are cancerous before removing them.

Drs. Sevick and Rasmussen hope that they and their industrial partners, NIRF Imaging Inc., based in Montgomery, Texas, and Exelis Inc. of McLean, Virginia—the leading supplier of military night-vision goggles—will have NIRF-LI on the market as soon as next year.

Other futuristic devices aren’t linked to military technology. The MINIR robot, being developed by Jaydev P. Desai, professor of mechanical engineering and specializing in robotics at the University of Maryland, can remove brain tumors while causing minimal damage to healthy tissue. The robot is made of plastic so that it can be deployed in the brain while the patient is in a working MRI machine. A physician would view the brain and the robot on the MRI interface, and remotely control the robot toward the tumor. The robot would then electrocauterize the tumor and be guided back out.

The robot, whose prototype resembles a small finger, is called MINIR for “Minimally Invasive Neurosurgical Intracranial Robot.” Some tumors can’t be reached by common surgical approaches. “When surgeons try to get to a tumor, in the process you may cause trauma to normal brain tissue,” Dr. Desai says. “Our challenge is can we get to that location while minimizing the trauma and then can we get the tumor out.”

Another device Dr. Desai is working on is a special catheter. Physicians now use a catheter, which is thin and flexible, to get into the body, for example, into a vein.

What if you had the ability to control how to bend a thin robotic catheter with an integrated diagnostic or therapeutic device or both,” he says.

This steerable, robotic catheter could send in an optical coherence tomography probe for diagnostic imaging. That would let a surgeon better see what is happening inside the body. A catheter that can bend at a surgeon’s will “can get around structures in the body that you want to avoid,” Dr. Desai explains.

*For more from Catherine, contributors from the Economist Intelligence Unit along with industry experts, join The Future Realities discussion.

Facade Design and Fabrication: The Expensive Disconnection

By Patrick

Facade design

Most BIM (Building Information Modeling) technologies today disconnect the production of permit drawings from the processes for fabrication and installation. When owners include subcontractors in preconstruction services (as they often do with general contractors) they have the ability to coordinate these activities and reduce errors.

What is needed then is a data backbone to connect the building design to the fabrication detailing and installation sequences. It is common practice to have architects design a facade, independently from the manufacturer who fabricates the facade, and also independently from the general contractor and subcontractors who install the facade system.

Construction projects have included waste levels of more than 25%, and a major portion of that waste is related to the building envelope and facade. Waste consists of redundant document production, unused stored materials, idling workers, rework of installations, and other factors.

Tweet: A major portion of construction project waste is related to the building envelope and façade #LeanCon @Dassault3DS http://ctt.ec/3_aQU+

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Owners and general contractors need to understand how much waste is connected to facade design engineering and planning processes.

New Contract Structure

The Design-Bid-Build relationship is the traditional contract model. Unfortunately, it makes it difficult for owners to drive project efficiency because of a lack of transparency in business processes and cost management systems.

In these circumstances, no one can take ownership of cost management over the entire life of a construction project. The Design-Build-Operate relationship is one answer to this issue.

In this form of agreement owners have the ability to coordinate the work of general contractors, subcontractors, building product manufacturers, operation and maintenance companies, and other stakeholders, in order to find a better way to deliver projects.

This approach makes building construction more like large scale product manufacturing, which historically has had much less waste.

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Information Exchange Problems

When facade design engineers make fabrication documents, information exchange is a critical issue. If a building has a complex facade shape, it is important to seamlessly generate accurate 3D geometry and to produce specific 2D drawings for CNC cutting machines.

Current BIM software has limited capability to produce 3D geometry appropriate to fabrication. Therefore it makes sense for architects to access libraries of parts used by a manufacturer rather than creating similar information from scratch.

It is hard for facade design engineers to adapt to frequent design changes and reproduce facade production documents on the fly, unless they are directly connected to the architect’s model.

Installation Planning

Installation is, of course, an important perspective from which to improve productivity. If the unique types and shapes of facade panels grow in number and variety, it becomes increasingly difficult to manage onsite installation.

If delivery sequence and installation processes of panels are not managed well onsite, it is hard to understand which panels should be installed in which positions. This could result in a large waste of time and resources.

To compound this problem neither manufacturers nor architects include cranes, scaffolds, and other installation equipment in the documents. This third data source must also be included to optimize the delivery process.

In summary, we need new contracts, new processes, and new tools to address the massive amount of waste in building construction. The separate processes of design, fabrication detailing, and installation planning need to be combined into a single environment to properly understand costs and risks in building projects. A promising solution for such an environment is on the cloud.

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Related Resources

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